Why do i keep getting negative pregnancy tests

A white circle with a black border surrounding a chevron pointing up. It indicates 'click here to go back to the top of the page.'

Índice Show

1. Completing a test too early
2. Irregular cycles
3. Ectopic pregnancy
4. Breastfeeding
5. Expired or mishandled test
What can cause a delayed period

Ideally, you should take a pregnancy test first thing in the morning. Zave Smith/Getty Images

Home pregnancy tests are usually accurate, but researchers estimate that up to 5% of tests give a false negative — meaning the test says you aren't pregnant when you actually are.

There are a few reasons why you might get a false negative. You might be taking the test too early or after drinking too much water.

The best way to ensure an accurate at-home pregnancy test result is to carefully read the instructions on the box and follow them correctly.

Here are several reasons why you might get a false negative and how you can properly take a pregnancy test.

Pregnancy tests work by measuring the levels of the pregnancy hormone human chorionic gonadotropin (hCG) in your urine. The amount of hCG in your body starts to increase once a fertilized egg implants in your uterus, and can be detected about 10 days after conception.

Where you are in your cycle also matters. "Most pregnancy tests will perform well if it is at the time of your missed period, which would typically be 2 weeks after ovulation or 28 days after your last period started," says Pamela Berens, MD, an OB-GYN with UT physicians and the McGovern Medical School at UTHealth in Houston.

If you take a pregnancy test before this time, you might get a negative result, even though you're actually pregnant.

Your pregnancy test should come with instructions about how long you will need to wait between taking the test and checking your results — the wait time is usually about one to two minutes. This is because the antibodies in the test need time to sense the hCG in your urine and display a result.

If you check the test before the waiting time is up, you may see a negative result even if you're pregnant.

To get an accurate positive result from a pregnancy test, you need to have a high concentration of hCG in your urine, which can be affected by several factors.

Your urine has the highest concentration of hCG levels first thing in the morning. "If you can't take a test in the morning, try to use urine that has been sitting in your bladder for around four hours.
Drinking lots of fluids can dilute your urine and lower the concentration of hCG, so it's best to avoid drinking too much water or other drinks before taking a pregnancy test.

If your pregnancy test is expired, it might give a false negative result. This is because the antibodies in the test that react to hCG hormones slowly evaporate over time — eventually there will be too few antibodies to accurately sense hCG.

You should always check the expiration date on a pregnancy test before using it to make sure you're getting an accurate result — they will often expire after a year or two on the shelf.

Pregnancy tests may also be defective. However, this is more the exception than the norm since many tests come with a control indicator to prove that the pregnancy test is working properly. This indicator may show up as an additional line that appears next to the test line or a symbol that appears in a window, depending on the type of test you take.

To get the most accurate result on a pregnancy test, it's important that you follow the instructions that come with the test. Here's a round-up of what to remember before taking the test.

Wait until at least 10 days after your last unprotected sex session to take the test.
Take the test first thing in the morning or after holding your urine for at least four hours.
Before starting, check the expiration date on your pregnancy test.
Read all the instructions that come with the test to make sure you're using it correctly.
Pee on the test stick for the recommended amount of time.
Place the test stick down and set a timer for the number of minutes the test requires.
When reading the test, first look for the control indicator to make sure the test is working.
Read the test, carefully following the instructions for how to interpret it.
If the test results are unclear, wait a day before trying again with another test, or reach out to your doctor for a follow-up.

If you aren't pregnant, your period should usually come about 28 days after your last period started. If your period is late, it may be a sign that you're pregnant, but there are many other reasons for a late period.

"If [a late period] is unusual for you, then you should probably see a doctor," Berens says, adding that weight changes, thyroid disease, and hormone imbalances could also be to blame for an irregular period.

Your doctor can also conduct a pregnancy blood test, which is more sensitive to hCG and can double-check your urine test result.

Getting a false negative on a pregnancy test is relatively rare, but it is possible, particularly if you take a test soon after ovulation. To reduce your risk of a false negative, take the test first thing in the morning and follow test instructions carefully.

False negatives are usually caused by testing errors, and medications like birth control or antibiotics shouldn't make any difference.

But certain fertility drugs, such as Novarel and Pregnyl contain hCG, which can lead to a false-positive result, where the test says you're pregnant when you really aren't.

Home pregnancy tests are very accurate if done according to the package instructions and if completed at the right time, i.e. the first day after the period is due and onwards after that. However, to confirm a result, the best thing to do is to repeat the test three to five days after the first test.

Even though urine tests are usually accurate, there are other unexplainable changes to your menstrual cycle that can cause concerns and doubts with the result, like when your test is negative, but your period is still late.

The best way to confirm a suspected pregnancy is with a blood test that confirms the presence of bHCG hormones in the blood. However, below are some reasons why a home pregnancy test can show a negative result when you are, in fact, pregnant:

1. Completing a test too early

This is one of the most common reasons for a false negative test. Many women will complete a pregnancy test as soon as they feel symptoms of early pregnancy, like sore breasts or changes to vaginal discharge.

However, the best way to guarantee a correct result is to wait for your period to be late, and then to do the test a few days later. This allows the body enough time to produce sufficient HCG hormones to be detected in a urine test. Read more about how to correctly complete a home pregnancy test.

2. Irregular cycles

When your menstrual cycle is irregular, negative pregnancy tests are actually more likely to occur. This is because, just like above, the urine test is completed too early, before a period is actually late, resulting in a negative test.

If you cycles are usually irregular, you should only complete a test two to three weeks after your predicted period. You should track your period symptoms to have a better understanding of when your period is due to start.

3. Ectopic pregnancy

An ectopic pregnancy is a rare condition. It occurs when a fertilized egg implants outside of the uterus, usually in the fallopian tubes. In these cases, the body takes longer to produce HCG hormone, and the result can appear negative even if fertilization has occurred.

This type of pregnancy is a medical emergency that should be terminated as soon as possible, as it can cause serious damage to the woman’s reproductive system. A few signs that can indicate a possible ectopic pregnancy are intense abdominal pain, vomiting, vaginal bleeding, or feeling of abdominal heaviness. If you have these symptoms, proceed immediately to the hospital to confirm diagnosis and initiate treatment.

4. Breastfeeding

When a woman is breastfeeding, the body takes longer to return to its initial pre-pregnancy state. Therefore, it is possible for a woman’s cycle to be irregular initially, even though she used to have a regular cycle before.

This may result in a false negative, as an expected period is not actually delayed yet, leading to an early pregnancy test.

5. Expired or mishandled test

This may be the rarest cause, however it is possible that a pregnancy test has expired and no longer functioning properly. When a test is not used vy its valid date, the presence of HCG may not be detected, resulting a negative test.

It is very important to check the expiration date on the package before using it. Additionally, if pregnancy tests are not stored properly, even though they are within the expiry date, they may not give an accurate result. For those reasons, if you suspect that the test is not reporting the correct result, you should complete another one.

What can cause a delayed period

If your period is delayed and a pregnancy test confirms a negative result, you are advised to repeat the test in a few days. If the second test is still negative even when your period is still late, likelihood of pregnancy is low. There are many factors that can influence your cycle and cause a delayed period when you are not pregnant.

Some causes of a delayed period are:

Excess stress and anxiety;
Practicing intense physical exercise for a long time;
Thyroid problems;
Very restrictive diets.

Learn about what else can cause a late period.

If your period is late and multiple home pregnancy tests confirm a negative result, you should consult your doctor to identify whether there is another factor influencing the delay. They may be able to indicate appropriate treatment based on the diagnosis.