How long after getting pregnant do you miss your period

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.

Will a pregnancy test work if I'm on the pill?

Yes.

Some methods of contraception, such as the contraceptive pill, contain hormones, but these hormones will not stop a pregnancy test working.

No method of contraception is completely effective, so it's important to take a pregnancy test if you think you might be pregnant.

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

Taking a pregnancy test can be filled with excitement for some people, whereas for others it may be a little intimidating. Before you take a pregnancy test, you might check to see if you are experiencing any pregnancy symptoms. A missed menstrual cycle is the most common symptom leading a woman to take a pregnancy test.

How does a test tell if you are pregnant or not?

A pregnancy test detects the presence of a hormone called human chorionic gonadotropin (hCG) in your blood or in your urine. hCG is produced in the placenta shortly after the embryo attaches to the uterine lining and builds up rapidly in your body in the first few days of pregnancy.

How long do I have to wait before I take a test?

Most doctors recommend that you wait until the first day of your missed period before taking a home pregnancy test. A missed period is usually one of the first signs of pregnancy. This is usually around two weeks after conception.
However, some tests are more sensitive than others and can be taken earlier. Concentrations of hCG are reported in milliInternational Units (mIU) or an amount equal to 1/1000th of an IU per milliliter. A pregnancy test with a sensitivity of 20 IU/L is more sensitive than one with 50 IU/L.

A blood test administered by your doctor is more sensitive than the early home tests and can be taken between 7 and 12 days after you conceive.  However, it is possible that these tests can be done too early and show a false negative result.  If you receive a negative result and still do not start your period, another test should be done.

How accurate are home tests?

Home tests are very accurate (around 97%) when used correctly. Some kits come with two tests because mistakes do happen. If you take a test too early, you may get a false negative (when the test says you are not pregnant but you are).
Your body needs time for the hormone to rise to a high enough level to be detected in a test. If the test comes back negative but you still think you could be pregnant, wait a few days and test again.

False positives (when the test says you’re pregnant but you’re not) are possible but rare. A positive pregnancy test is a pretty good indication that you are pregnant.

Do you want to get pregnant?

Our Ultimate Fertility Resource Guide provides the information you need on fertility, tips on how to get pregnant faster, and how to boost fertility through sometimes simple tweaks to your lifestyle and approach. The guide is easy to read and meant for anybody wanting to increase their ability to conceive. It’s a free download and includes coupon codes for essential products. Even free Nightfood Nighttime Ice Cream.

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