How late can you get a false negative pregnancy test

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01/4Morning vs Night

The decision of when to take the pregnancy test to get an accurate result can at times be a major source of anxiety. Whether you are eagerly waiting to get pregnant or you don't want to get pregnant, in both cases, the last thing you want is an inaccurate result. Most of us rely on a home pregnancy testing kit to get the primary confirmation, only after this we opt for proper lab testing. Urine home pregnancy tests are about 99 per cent accurate. But at times it can be influenced by factors like the irregular menstrual cycle, low hormone level, lifestyle factors and others. According to popular belief, taking a pregnancy test in the morning is the best as the chances of getting a false negative is higher at night. Here we have tried to figure out how much truth is there in this claim.

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02/4​Can you take a pregnancy test at night?

It is alright to take the pregnancy test at night, but whether doing so can be a reason for the negative result or not is yet unclear. That's because the home pregnancy test responds to the level of human chorionic gonadotropin (hCG) present in your urine. The hormone is produced by the placenta and by the tenth day of the ovulation, the amount of hCG reaches a level where it can be easily detected by a home test kit. Taking the test in the morning is mostly recommended because of the concentration of the urine. Since you would not have drunk water or pee at night, the level of hCG will be higher in the urine and it will be easy to detect if you would be pregnant. At night, your urine would be diluted and the level of hCG would be low, leading to negative pregnancy.

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03/4​What to do if you test negative at night

The at-home pregnancy test kit mostly gives accurate results, but the chances of getting a negative pregnancy still remain. If you are trying to get pregnant or witness any pregnancy-related symptoms and your test kit shows a negative result, we recommend you to take another test in the morning or after a few days. Several things can influence your result and can give a negative result like taking a test too early, not following the direction and others.

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04/4​The best time to take a pregnancy test

The best time to take the pregnancy test is after your period is late. Some test kits show positive results within 4 or 5 days before your period is due. But taking the test after a missed period is better to get a more accurate result and avoid false negatives. In case of irregular menstrual cycles, wait 35 to 40 days before taking the test. Taking the test in the morning is more preferred over the night to get an accurate result.

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If you have missed a period and recently had unprotected sex, you may be pregnant. Pregnancy tests are most reliable from the first day of your missed period.

When you can do a pregnancy test

You can carry out most pregnancy tests from the first day of a missed period. If you don't know when your next period is due, do the test at least 21 days after you last had unprotected sex.

Some very sensitive pregnancy tests can be used even before you miss a period.

You can do a pregnancy test on a sample of urine collected at any time of the day. It doesn't have to be in the morning.

Where you can get a pregnancy test

You can buy pregnancy testing kits from pharmacists and some supermarkets. They can give a quick result and you can do the test in private.

The following places provide free pregnancy tests:

  • sexual health services
  • some young people's services – call the national sexual health helpline on 0300 123 7123 for details
  • Brook centres for under-25s – find your nearest Brook centre

You may also be able to get a pregnancy test free of charge from your GP.

How does a pregnancy test work?

All pregnancy tests detect the hormone human chorionic gonadotrophin (hCG), which starts to be produced around 6 days after fertilisation.

Most pregnancy tests come in a box that contains 1 or 2 long sticks. You pee on the stick and the result appears on the stick after a few minutes. All tests are slightly different, so always check the instructions.

Pregnancy test results

Home pregnancy tests are accurate as long as you follow the instructions correctly.

A positive test result is almost certainly correct. However, a negative test result is less reliable.

The result may not be reliable if you:

  • do not follow the instructions properly
  • take the test too early

Some medicines can also affect the results.

If you get a negative result and still think you're pregnant, wait a few days and try again. Speak to your GP if you get a negative result after a second test but your period has not arrived.

Continuing with the pregnancy

If you're pregnant and want to continue with the pregnancy, contact your GP or a midwife to start your antenatal care. You can use the pregnancy due date calculator to work out when your baby is due.

If you're not sure you want to be pregnant

If you're not sure about continuing with the pregnancy, you can discuss this confidentially with a healthcare professional. Your options are:

  • continuing with the pregnancy and keeping the baby
  • having an abortion
  • continuing with the pregnancy and having the baby adopted

As well as a GP or a nurse at your GP surgery, you can also get accurate, confidential information – from the age of 13 – from the following:

  • sexual health services
  • the MSI Reproductive Choices website
  • the British Pregnancy Advisory service website
  • the National Unplanned Pregnancy Advisory service website

All these services – including community contraceptive clinics – are confidential. If you're 13 or older, the staff won't tell your parents. They'll encourage you to talk to your parents, but they won't force you. 

If you're under 25 and would prefer advice specifically for young people, the sexual health charity Brook provides a range of services for young people. The Brook website contains information on pregnancy choices. You can also use the Ask Brook 24/7 service.

Video: Is the pregnancy test accurate?

In this video, a midwife explains when you can take a pregnancy test and how to do it properly.

Media last reviewed: 5 February 2020
Media review due: 5 February 2023

How long can a pregnancy test show a false

Your hCG won't be high enough to detect until six days after conception. If you took the test too early, then the test will read negative even if you are pregnant. The test is fine-tuned to detect low amounts of hCG, but there aren't enough hormones to be detected on the test until about a week after conception.

Can you get a false

Yes, it is possible. Getting a negative result doesn't mean you're not pregnant, it may just mean your hCG levels are not high enough for the test to detect the hormone in your urine.

Why am I late if my pregnancy test is negative?

Reasons Your Period Might Be Late (That Don't Include Pregnancy) The most common reason for a late period and a negative pregnancy test is that your period is simply delayed and you're not pregnant. Having one or two irregular cycles a year is not unusual and does not mean there is something wrong.

Can you be 7 weeks pregnant and test negative?

Around the 5th to 7th week of gestation, however, urine concentrations of an hCG variant known as the hCG beta core fragment rise dramatically, interfering with hCG detection and causing false-negative test results.