Is it possible that a pregnancy test does not show pregnancy. What day does the test show pregnancy after conception? Pathological delay factors

In our time, several methods have been developed for the early diagnosis of pregnancy. One of the most common and convenient, which women really like because it can be done at home, is a pregnancy test. Manufacturers claim that the reliability of the test is 99%. This means that an error is very unlikely.

But the situation is very common when the delay is several days, and the test shows the absence of pregnancy, and this is preceded by several reasons.

Whatever test manufacturers claim, early pregnancy diagnosis using tests can give a false result. Currently, doctors are very suspicious of the results of pregnancy tests, relying mainly on ultrasound and medical examination. These tests are developed on the basis of the diagnosis of pregnancy by determining the norm chorionic gonadotropin in the urine of a woman, subject to a normal pregnancy, this rate increases after the 7th day from the moment of fertilization. So it makes sense to wait until the delay period is at least 5 days in order for the result to be reliable.

There is also a possibility that pregnancy did occur, and the test shows the absence of pregnancy. The reason for this may be a poor-quality test, the test is expired, or it was not stored correctly. Also on wrong result the correctness of the test is also affected. As a rule, the test must be carried out in the morning - on morning urine, and it is necessary to follow exactly all the instructions for conducting the test - strictly observe the time, lowering the test strip to the indicated level - no higher and no lower. Therefore, do not take the results of one test as a base, but conduct at least two checks with tests from different manufacturers.

Stress can be another reason for a delayed menstrual cycle. Conflict situations, quarrels, breakdowns on a nervous basis lead to the fact that an imbalance occurs in the woman's body, and, accordingly, to a delay.

Various gynecological diseases may also be the cause of the delay. These diseases include endometritis, polycystic ovaries, different kind tumors, ovarian dysfunction.

If a woman is taking medication, this may lead to a delay. many kinds medicines, especially hormonal preparations, affect menstrual cycle.

A very common reason for a delay is a sudden change climatic conditions. This can provoke a trip to the mountains or a trip to the sea. So in this situation, usually negative result test is expected.

As we can see, there are many reasons for delaying menstruation, and this is not necessarily pregnancy. organism healthy woman works like a clock and any deviations in the work of the body should be carefully listened to in time to reveal hidden diseases or ailments.

As a rule, a delay in menstruation is not a cause for concern. It is necessary to understand the reason that caused the delay. To do this, you should contact your doctor and undergo the necessary diagnostics and medical examination. It is possible to identify a disease that will require treatment. If a woman experiences frequent delays in menstruation, without obvious signs of pregnancy, this may be a signal of the presence serious violations in organism. Therefore, if the disease is not recognized in time, it can cause severe consequences in the body of a woman, and sometimes leads to infertility.

They say that women's intuition must be listened to. But don't always trust her. If a woman is almost sure that she became pregnant in the last menstrual cycle, then it is undoubtedly advisable to take a test and go through everything. necessary research to find out if this is true. However, in practice it happens that the test does not show pregnancy, and it is not at all excluded that intuition in this case turned out to be female suspiciousness.

Whether you are afraid of getting pregnant or passionate about it - any of these feelings in any case can affect female state. If there are still no planned regular periods, and the test still does not show pregnancy, then there is even more to think about.

In what cases the test does not show pregnancy: reasons

So, thousands of women turn to search engines with the question of whether it happens that the test does not show pregnancy. And we will answer this question for you right away: yes, it happens, and even quite often - much more often than vice versa, when the test shows a non-existent pregnancy. But why this happens is not so easy to find out. The reasons are very different.

All home tests are built and work on the same principle: they contain a reagent that reacts with a specific hormone - hCG (human chorionic gonadotropin). If a woman is healthy, then normally a very small amount of hCG may be present in her body. The level of this hormone begins to increase rapidly only after the onset of conception, because the future embryo actively produces it.

In the first days after conception, the concentration hCG hormone doubles every two days. At first, it rises in the woman's blood, and after a few days it becomes quite high in the urine. The test is able to determine the presence of the hormone hCG in the urine of a woman after about two weeks from the moment of fertilization.

Considering that ovulation in most cases occurs approximately in the middle of the cycle, it makes no sense to carry out the test earlier than after the onset of the delay: by this time it will be possible to determine the presence or absence of pregnancy using this home method. Doctors urge women to do testing only 2-3 days late or even later. And at the same time they warn: all previous studies may be unreliable.

However, a huge number of women carry out a pregnancy test before a delay in practice. And he actually often shows true result. And we are already so accustomed to this that we consider holding early testing the norm. Meanwhile, even in the instructions for the most highly sensitive tests, which can be performed even before the delay and at any time of the day, it is recommended to do the test only after the delay. Otherwise, the abstract warns, the reliability of the results is significantly reduced.

If the test does not show pregnancy before the delay, then this reason should be suspected in the first place: testing too early. Add to that the probability late ovulation in the last cycle, and it is better not to panic prematurely. Wait for periods, and in case of their absence, repeat testing for 2-3 days of delay, and then again a week later.

Why the test does not show pregnancy, but there are signs

The closer to the expected start of menstruation, the more sick, the mood changes more often and the nervousness becomes stronger. The list of sensations that a woman can experience in the first days after conception is very large. But it should be recognized that all of them with the same degree of probability can be premenstrual syndrome. Reproductionists very often observe a picture when women trying to get pregnant look for mythical early signs of pregnancy in almost every cycle and conduct many tests. There is even the concept of "false pregnancy" when, due to psychological mood there is indeed a delay. Girls behave in a similar way, whose plans do not include pregnancy at all: because of fear, they are able to see signs where there are none.

Dear ladies, in any case, you should put emotions aside and assess the situation as objectively as possible: nausea, dizziness, irritability and drowsiness can have thousands of other reasons that are completely unrelated to pregnancy. It is better never to set yourself up for any particular result and not to jump to conclusions. In a word, the signs of pregnancy may not turn out to be such at all - keep this in mind. In addition, today more and more women experience hormonal disruptions, which can lead to the slightest stress.

However, than more days the delay lasts, the more suspicion turns into certainty. Only one thing is confusing: although there are no periods, the test still does not show pregnancy.

Always remember that pregnancy in reality may not be, no matter how much you are sure of it. Hormonal disruptions in women happen quite often, the menstrual cycle may well go astray and move forward several days, and there are a number of reasons for this - from illness to changes in weather or climate.

But, of course, even with a repeated test, which showed a negative result, pregnancy can be.

Test results showing no presence an existing pregnancy are called false negatives. The instructions for any test, as a rule, indicate in which cases and for what reasons the test may not show a pregnancy that actually exists. Most often these reasons are:

Too much early testing (which we have already discussed above): the level of hCG in the urine is not yet high enough to be determined by the test reagent.
Violation of testing rules. Each package contains a simple, clear, detailed step-by-step instruction how to test properly. If this is a strip, then it must be immersed in urine strictly up to the indicated mark. If the cassette says to apply 3 drops to the display, then do just that. In addition, the urine collection container must be sterile, the test results should be read after and no later than the time specified in the instructions.
Poor quality test. Despite, and perhaps even due to the presence in pharmacies of a huge number of tests from various companies, not all of them are of the same quality. And the price here may not always be an indicator of quality. Girls often share their experience that it was the simplest cheap test that showed the first pregnancy, while the “fancy” one was wrong. Also, be aware that the test may have been mishandled and always check the expiration date.
"Diluted" urine. To maximize the reliability of the result obtained during testing, it is best to diagnose using the first portion of morning urine. It is considered the most concentrated (unless you have been drinking all night and have not gone to the toilet in a small way without getting tired), which means that it may contain the most hCG hormone. In this regard, also consider that taking diuretics and eating foods / drinks that have a diuretic effect can affect the result of the test: it may not detect the hCG hormone in very “diluted” urine.
Late ovulation in the last menstrual cycle or late implantation of a fertilized egg. If the egg matured later than expected, or after fertilization, it got to the uterus longer than usual, then due to its late implantation, hCG will begin to be actively produced a little later - and the test, accordingly, will be able to show pregnancy later.
Diseases of the heart or kidneys. In some diseases of the cardiovascular or urinary systems, the hCG hormone is not produced in sufficient quantities or is not able to penetrate into the urine, which causes a false negative result. If you have chronic pyelonephritis, or you have recently been seriously ill, then it is likely that the test will not show pregnancy.
Violations during pregnancy, in which an insufficient amount of the hCG hormone is produced, which is why the "test" does not see pregnancy. It can be an ectopic, missed pregnancy, abnormalities in the development of the fetus. Short hCG level observed with the threat of miscarriage.

We would like to draw your attention to the fact that most often the reasons that the test does not show pregnancy, when there are both signs and a delay, are quite harmless. Just the process of ovulation and implantation gestational sac in each individual case may have its own characteristics.

The last reason we talked about is the start abnormal pregnancy- occurs much less frequently. However, this possibility must be ruled out. Therefore, in the absence of menstruation on time, even if the test does not show pregnancy, it is recommended to visit a gynecologist. Perhaps he will refer you to a blood test for hCG or an ultrasound, which will allow you to find a more accurate answer to your question.

How long can a test not show pregnancy

The modern woman is no longer satisfied with such a " early diagnosis”, when she finds out about pregnancy even before the appearance of a visible tummy. Today, without exception, everyone wants to get an answer to an exciting question a few more days before the delay. That is why they start conducting pregnancy tests too early. There are frequent cases when, before the appearance of true two stripes, a woman manages to conduct about a dozen tests, or even more.

We urge you not to force things yet, and for this reason: in some cases, the test may not show pregnancy for a very long time. A few weeks (from one to three) is an average. But in some cases we are talking about months! At the same time, a baby develops safely in the womb of a woman, so carefully hiding her existence from her mother. Moreover, occasionally even hCG and ultrasound are not able to discern a pregnancy in the first weeks of its development, despite the fact that there are no pathologies.

You can never rely only on test results, even if they showed the result you expected the first time. Only gynecological examination and further examinations may put a definitive dot or ellipsis followed by "to be continued". And therefore, it simply does not make sense to deliberately set yourself up for some specific result: unnecessary worries do not solve anything, and in the event of a pregnancy, they are also not safe.

Especially for - Elena Semenova

Is it possible to be sure that a pregnancy test is not mistaken when it shows only one strip? And what to believe, the result of an ultrasound, a test, or in general own feelings?

The onset of pregnancy in all cases is accompanied by an increase in the level of chorionic gonadotropin in the woman's blood. This hormone is produced by the chorion, the membranes of the baby, and in the first days of pregnancy, its quantity increases rapidly, and of course, it enters the urine. On its determination in the urine, the work of all pregnancy tests is built.

It happens that a woman is convinced that there is a pregnancy, but the test does not show. The reasons for this may be different.

In what cases the test does not show pregnancy?

. Since pregnancy tests only work with the beginning of the formation of the fetal chorion when a certain concentration of hCG in the urine is reached, the test works approximately 14 days after conception, that is, already in the presence of a delay. However, sometimes for one reason or another, the cycle is disrupted, and ovulation occurs a little later than usual. And then, despite the delay, a sufficient period may not yet pass from conception, there is still too little hCG in the blood, and the test remains negative, despite the fact that you are pregnant and there is a delay.

Some women have naturally lower levels of hCG in their urine, which is why tests don't show pregnancy right away.

When the embryo is implanted, it does not take place in the uterus, but in fallopian tube, there is no endometrium, and the embryo cannot develop normally. For this reason, the level of hCG is growing more slowly, and many women who have undergone this pathology noted that their test did not show pregnancy for a long time. And yet, if the test did not immediately show pregnancy, you should not think about this reason in the first place, an ectopic is very rare.

If you have a delay, the test does not show pregnancy, it is possible that there really is no pregnancy, it is quite common that a woman. And there can be many reasons for this. Maybe you have been ill or stressed, perhaps you have hormonal disbalance maybe you have lost a lot of weight on a diet or are experiencing great emotional and physical overload. All of these can cause delays.

Sometimes a pregnancy test does not show pregnancy, because the test itself is of poor quality, expired or fake, this happens more often when buying cheap tests.

The chance of a test failing is reduced if done correctly. using the morning portion of urine, after 2-3 or more days from the delay of menstruation. Use from trusted manufacturers with a sensitivity of 10 IU. Buy them only in a pharmacy. If the test is negative, repeat in a week.

And of course, remember alternative methods diagnosis of pregnancy early term- Ultrasound and blood test for hCG.

Each modern woman in a hurry to use a pregnancy test when the slightest suspicion of its development appears. Of course, this is very convenient, since a visit to the doctor will take more strength and time than going to the pharmacy. In addition, the test result will be obtained quickly and accurately. But just about the accuracy of pregnancy tests, disputes arise. Some women complain that the tests failed them, showing an erroneous result. Why does the test not show pregnancy and in what cases does this happen?

Nowadays, pregnancy tests are available and popular. Due to the minimal cost, it is possible to short time learn about your situation. essence home study is to determine hCG - the hormone of pregnancy in the urine, which is produced in the body of each future mother from the development of the placenta and the implantation of the embryo.

The test may not show positive result in the presence of pregnancy. This happens for several reasons.

Reason 1: Test done too early

An unreliable result when using the test can be obtained due to the fact that the woman decided too early to conduct an appropriate diagnosis. Normally, the amount of pregnancy hormone (hCG) increases markedly by the time of the expected menstruation. That is why the test is recommended to be carried out no earlier than the first day of a missed period. In this case, the result will be the most accurate.

Some women neglect this rule and conduct a urine test much earlier. There are also situations when the level of hCG remains at a minimum for longer due date, then the test will demonstrate for some time false negative result. If there is any doubt (for example, the test does not show pregnancy, but there is a delay), the study is repeated after 48 hours, or a test from another manufacturer is purchased.

Reason 2: Unsatisfactory urine quality

If the test does not show pregnancy, but there are no periods, the reason may be in the composition of the urine. Excessive fluid intake before the study or the use of diuretic drugs can significantly affect the concentration of hCG in the urine. Therefore, a reagent that captures pregnancy hormones in the test fluid cannot detect them in the amount necessary to obtain an affirmative result.

For the study to be accurate, the test is best carried out in morning time with the first portion of urine, while in the evening it is not recommended to drink too much liquid and not take diuretics. Only under these conditions, the concentration of hCG in the urine will be optimal to obtain an unmistakable result.

Reason 3: Incorrect use of the test

If during the use of the test were violated elementary rules, which are described in the instructions, then various errors in the study are not excluded. For example, it is important to dip the test strip into the urine strictly to the mark and for the exact amount of time, do not touch the reagent area with your fingers to prevent dirt or sweat from getting on it, etc.

Reason 4: disorders in the urinary system

Diseases of the kidneys and other organs of the urinary system may affect the result of the study. For example, with kidney disease, the amount of hCG in the urine may remain at a minimum level. a long period time, so the test does not see pregnancy. Also, the result will be false negative if the woman's body has inflammatory process against the background of which protein is found in the urine.

Reason 5: problems with the development of pregnancy

Sometimes the test may not show pregnancy if it develops incorrectly, with deviations from the norm. We are talking about the implantation of the fetal egg, the threat,. In all these cases, the amount of hCG in the urine will not increase, so the test will not show such a pregnancy. If there is a suspicion of the presence and abnormal course of pregnancy (delayed menstruation, spotting, abdominal pain), you should consult a doctor, and not rely solely on express tests.

Reason 6: Incorrect storage of the test

A test just purchased at a pharmacy can be safely trusted, since all storage conditions must be preserved. If the test for a long time lay in a woman's purse or at home, that is, it was stored in conditions high humidity, could be subjected to temperature changes or simply turned out to be overdue - most likely, the result of the study will be unreliable. It is better to purchase tests for immediate use in the near future and not store them. long months Houses.

Reason 7: Poor quality or defective tests

Tests from different manufacturers may have significant differences in terms of quality, so the results of the study different tests may vary. If you need to get an exact answer, it is best to pay attention to different companies. At the same time, their cost practically does not play any role, both expensive and cheap tests can be equally good.

Why does the test not show pregnancy if there are obvious signs of it?

The whole range of sensations that women experience in the first days and weeks after conception is quite voluminous. But we must agree that all these symptoms with a high degree of probability may turn out to be banal PMS - premenstrual syndrome, familiar to every woman to one degree or another.

If a woman is terribly afraid of pregnancy or, on the contrary, simply dreams of becoming a mother as soon as possible, then in each cycle she will try to find out from herself early symptoms the onset of conception, which may turn out to be far-fetched. Such experiences can turn false pregnancy- mental disorder.

In this case, gynecologists recommend throwing emotions away and looking at the current situation with common sense: Irritability, dizziness, nausea and increased drowsiness can be associated not only with pregnancy. If the test does not show pregnancy, and the delay has already come, the right decision would be to consult a doctor to exclude hormonal disorders and possible definition pregnancy.

The test does not show pregnancy, but there is a delay

First of all, I would like to note that the test may not show the presence of pregnancy with an existing delay in menstruation. harmless reasons. For example, ovulation, and therefore the implantation of the ovum, took place a little later than it should be. Nothing wrong with that.

Secondly, women are often prone to failures in hormonal system. Hypothermia, stress, climate change, physical and mental overwork, illness - all this can affect hormonal background organism. For this reason, a woman's menstrual cycle can move several days or weeks ahead. This is the answer to the question why the test does not show pregnancy when a delay occurs.

Pregnancy is always exciting question. There are cases when it can occur even with a negative test. Every woman should carefully monitor her health and pay attention to the slightest sign ailments, unpleasant symptoms or unusual discharge.

To determine the position of a woman: whether she is pregnant or not, a test is capable of calculating the level of hormones in the female blood. The name of this hormone is human chorionic gonadotropin, abbreviated as simply hCG. It is realistic to calculate its concentration in the blood the very next day after fertilization, when the fertilized female cage attached to the wall in the uterine cavity. There are several ways to determine the amount of a hormone.

The simplest, most affordable and popular way is the test, which is easy to purchase at any pharmacy. It is sold without a prescription, its principle of action is quite simple and it is not expensive at all (in international currency, its cost starts from only $ 1).

easiest negative test

The principle of operation of such a test is quite simple: there is a substance on a stick - certain antibodies that interact with the "pregnancy" hormone in the woman's urine and display the result of their interaction on a white field with the help of a dye:

if there is only one lane no hormone in urine
if there are two stripes in the urine there is a concentration of the hormone and this means that the fetus is in the uterine cavity

It is possible that the test may show incorrect information. This happens most often because manufacturers produce low-quality tests or a defective product.

It often happens that pregnancy is present, but the test gives a negative result. This can happen even several tests in a row and the reason for this is not a quality product at all, but a physiological feature of the human body
The fact is that immediately after conception, a fertilized egg may not attach to the wall. She has ten whole days at her disposal for this action, and all this time she can calmly be in the cavity.
Only when the cell is attached, it forms a kind of protective shell - the placenta. It is the placenta that produces this "pregnant" hormone. Based on this, we can conclude that pregnancy tests are effective only a week or even two weeks after conception.
Unknowing women often jump to conclusions when they take a test on the second or third day and wait for the result.

The best time to test is a delay in the expected critical days. A delay, by the way, may not mean pregnancy at all, it is important to know that up to five days of delay are considered normal.

pregnancy test and determination

choose a test well-known manufacturer, which has many positive feedback and great work experience
always buy two tests at once, in case one of them turns out to be of poor quality
if you buy two tests at once, it is advisable to buy a product of different brands
test the urine collected in the morning - it contains the maximum concentration of biological components
carefully read the instructions and only then dip the test into urine, pay attention to the correct side of dipping and the required level mark
do not keep the test in the urine for too long, each manufacturer specifies the exact time of its dipping
after dipping the test, put it on a dry surface and exactly wait for the time after which the result should appear

Video: "How to take a pregnancy test?"

Negative test: is an ectopic pregnancy possible?

Gynecologists often diagnose an ectopic pregnancy in women thanks to the test. Of course the most exact result can only be obtained with the help of a thorough diagnosis and ultrasound, but there are still certain skills and knowledge that help to avoid rupture of the fallopian tube and avoid serious consequences
An ectopic pregnancy is very similar to a normal one, but it differs in that the fetal egg is not attached to the uterine wall, but in the tube leading to the uterine cavity. IN this case the hormone is also produced, but in a slightly smaller amount, and even the embryo develops. However, such a fetus is doomed to death, because its development is not normal and pathological.
It is worth noting that with such a pregnancy, the level of the hormone rises a little later than during normal pregnancy, about one to two weeks. But this is not essential when a woman is not at all aware of her pregnancy and only realizes this when a significant delay occurs.

how to determine an ectopic pregnancy in the early stages?

Based on this, women who regularly test and expect fertilization may notice the ambiguity of their test: it shows an “almost” positive result - one line is clear, the second is translucent. If enough time has passed for the development of the fetal egg, and the test does not give bright two bands, you should consult a doctor for advice.

The development of an egg on the mucous membrane of the tube is not normal. Such a pregnancy is extremely dangerous, it can cause irreparable harm woman and even threaten her life
The embryo in the fallopian tube, as a rule, develops with pathologies and is doomed to death.
The fact that a woman has such a pathology is most often influenced by factors such as: mature age(from thirty-five years old is a kind of “risk group”), the presence of inflammatory and infectious diseases urinary-genital system, as well as the abnormal development of the internal genital organs of a woman
There is another opinion of doctors, which claims that female contraception, a spiral, affects the appearance of this type of pregnancy.

schematic representation uterine cavity

It should be noted that an ectopic pregnancy can be in several cases, the fetal egg is attached in places that are abnormal for it:

Fallopian tube- the most common phenomenon, which has a frequency in 99% of cases
in the "uterine horn" - part of the fallopian tube
in the ovary very rare occurrence
in the abdominal cavity

Such a pregnancy is difficult to determine by feeling unwell, since all the symptoms are similar to the symptoms normal flow pregnancy. Unfortunately, it always tends to burst and tear. It happens with the strong sharp pains and hemorrhages in the abdominal cavity.

Video: "Ectopic pregnancy signs, symptoms and advice from doctors"

Delayed menstruation and negative test: is pregnancy possible?

Every woman has experienced a pregnancy test at least once in her life. For some, the test is of great importance and the thrill of waiting for the appearance of a child in the family, for others it is an undesirable event. In any case, when making a test, you need to be aware that there are situations when the test is capable of giving false or incorrect information.

In most cases, a woman begins to take a test when she notices a delay in her cycle. In addition to this symptom, a woman may also feel unwell: nausea, pain, toxicosis.

clear signs And negative test

It is worth noting that if the test is not done correctly or a poor quality test is bought, it is quite capable of giving a false result. If you are sure that you are purchasing a quality test, pay attention to factors such as:

his sensitivity is different manufacturers have different degrees of sensitivity of the test, this can affect the result. In order to get the best result, you should purchase a test that gives a 99.9% probability
the deadline for it - some are allowed for use already in the first weeks, while others only after fourteen
test time - some tests allow analysis at any time. time of day, and others only in the morning, when, after a long retention of urine, it concentrates the largest number hormone
its expiration date This important factor, affecting the correct result during the test, if its expiration date has expired, it will quite possibly show you a false result

Remember that each organism is individual and the effectiveness of the test depends on physiological features women.

Menstruation can stop not only because of pregnancy. Before you take a test and suspect it, examine yourself for other factors that affect the delay:

Climax - hormonal failure of a woman's body, after which menstruation simply disappears. In some cases, they reappear, but after a while they can disappear again. These feelings can last up to a year.
Polycystic - the occurrence of cysts (tumors) in the ovaries that disrupt their normal functioning and affect the hormonal background
Anemia - is a deficit and low level hemoglobin in the blood. The woman's body tries to keep the maximum amount of blood and menstrual flow is quite scarce or may not be at all.

Video: “The menstruation disappeared. Ten reasons. What to do?"

Can I take a pregnancy test during my period?

IN women's practice it also happened that pregnancy occurred even when the body produced monthly bloody issues. This is a reason to worry about whether it is necessary to do a test during menstruation?

test during menstruation

During menstruation test for determination of hCG do not prohibited. The fact is that the discharge does not affect the concentration of the “pregnant” hormone in the body.
The main thing that prevents this test is the hygiene of the process.
For this reason, before doing a test during menstruation, you should use a tampon.
If bleeding get into the urine, they can significantly affect the performance of the test
You should pay attention to other signs of pregnancy and a woman’s poor health: toxicosis, headaches, soreness and breast filling, spasms, changes in taste preferences
Pay attention to the nature of the discharge, if it is abundant and strong - it is more like menstruation, and if it is scarce and bright red - it is quite similar to a small bleeding that occurs during implantation of the fetal egg to the uterine wall

In any case, you can do a test during menstruation. However, you need to know that during pregnancy, menstruation is always not good, you should consult a doctor to avoid the complications that this symptom can bring.

Video: "Monthly during pregnancy"

If 2 tests are negative, can there be pregnancy?

It is not uncommon for a woman to repeatedly take tests before pregnancy and they all turn out to be negative. To her surprise, after the time has passed, she finds out that she was pregnant after all. What is the reason for such negative tests?

As a rule, many factors influence the effectiveness of the test, and a negative result can show:

overdue test- in which the active substances have become unusable because a lot of time has passed since the moment of manufacture
insensitive test - it works only when a lot of time has passed since fertilization and in order to get the most accurate result, you should choose a test with 99% truthfulness
taking certain medications at the time of the test, in this case we are talking about hormonal drugs
misuse test allows you to get an inaccurate result

Is it possible to have a negative pregnancy test?

After you have tested negative several times, but eventually discovered that you are pregnant through a blood test or ultrasound, you should consult your doctor for advice.

Video: “Do pregnancy tests lie?”

Ovulation test is negative, is pregnancy possible?

The ovulation test differs significantly in its principle of action. If, in the case of fertilization, the test determined the presence of human chorionic gonadotropin in the woman's body, then the test for ovulation is aimed at calculating whether the egg has entered the uterine cavity
There are two types of such tests: strips and cassettes. Cassettes are more sensitive and give the woman more accurate information. They differ in that they are much more expensive than ordinary strips.
This test also requires dipping it in urine. There are also reusable tests with a set of several strips.

ovulation test strips

As a rule, an ovulation test shows the concentration of the hormone estrogen, which is present in the body, focusing on the state of the egg. When the egg enters the uterine cavity, its number is maximum, which means that the most auspicious time in order to conceive a child.

If the ovulation test shows a negative result, then there is no chance of getting pregnant. However, every woman needs to know that the male seed is able to live in the uterine cavity for up to two or three days, and if after this time the egg still descends into the cavity and there is a viable sperm in it, pregnancy is possible.