Where to get a reliable pregnancy test

Pharmacies and some supermarkets will sell pregnancy testing kits. You can access free pregnancy tests in community contraceptive clinics, sexual health clinics and Brook centres (for under 25s).

How a pregnancy test works

When you are pregnant, your body produces a sudden increase in a hormone called human chorionic gonadotrophin (HCG). HCG is a hormone that is produced initially by the developing embryo and then later by the placenta; it starts to be produced around six days after an egg is fertilised. HCG flows throughout your bloodstream and urine (home pregnancy tests measure the level of HCG in your urine, which rises more rapidly as you progress further along in your pregnancy).

Find out more on our Hormones and the Menstrual Cycle page.

When to do a pregnancy test

You can do a pregnancy test from the first day of your missed period. If you perform a pregnancy test before this, the results are not always accurate. If you do not have regular periods and you are unsure when your period is due, it is a good idea to wait at least three weeks after when you think you may have conceived.

How to do a pregnancy test

Pregnancy tests will generally come with instructions on how to perform the test; it is a good idea to read the instructions carefully before carrying out the test.

Most pregnancy tests will require you to pee on the test stick for 5-10 seconds or to pee in a cup and put the pregnancy test stick inside it for up to 10 seconds. It is usually best to perform the test first thing in the morning as this is when the HCG or ‘pregnancy hormone’ levels are at their highest concentration. Drinking too much fluid beforehand can also dilute the concentration of HCG in the urine, so try to avoid over-drinking prior to the test.

Is there any difference between a home pregnancy test and a GP’s test?

Pregnancy tests at home detect urinary HCG. GPs can perform urinary pregnancy tests (similar to the ones performed at home) and also blood pregnancy tests.

Blood pregnancy tests can confirm the presence of HCG in the blood as well as show the exact amount of HCG in the blood. A level of HCG above 25 mIU/ml will indicate that you are pregnant. If the HCG level is between 5 and 25 IU/ml, you will generally be asked to do another blood test, 48 hours later.

A blood pregnancy test is not always necessary, but it may be recommended if you are at high risk of miscarriage or ectopic pregnancy.

How long does it take to get a pregnancy test result?

With home pregnancy tests, it generally takes a couple of minutes for the test results to appear.

If your doctor has performed a blood pregnancy test the results may take two to three days.

Interpreting pregnancy test results

Traditional home pregnancy tests will come with one or two windows on the pregnancy stick.

One test window
A test line in the window allows you to check that the pregnancy test stick is actually working. A ‘positive result’ will show both the test line and another line side by side indicating that you are pregnant. A ‘negative result’ will only show a single test line indicating that you are not pregnant.

Two test windows
In one window, a test line will appear for you to check that the pregnancy test is working. In the second window, if you have two lines making a ‘+’ sign in the window, this shows a ‘positive test result’. If there is a single line in the window, it shows a ‘negative test result’.

Recently, digital pregnancy tests have become increasingly popular as they are easier to read, and do not require interpretation of test lines. A ‘positive result’ will say ‘you’re pregnant’ or ‘yes’, and a negative pregnancy test will say ‘not pregnant’ or ‘no’.

How accurate are pregnancy test results?

As long as you follow the instructions provided, pregnancy tests are highly accurate. A positive result will almost certainly be correct, but a negative result is less reliable.

A test result may be less reliable if you have not read the instructions clearly before carrying out the test, or if you take the test too early when the level of HCG in the urine is too low to be detected.

Do you need to take more than one pregnancy test?

If you have a positive result, it is almost certainly correct so you do not need to take more than one test. However, if you have a negative result, but you still think that you are pregnant, you may wish to repeat the test after a few days. If you have a negative result on a repeat test and your period hasn’t started, you may wish to speak to your GP.

False positives and false negatives

A ‘false positive’ is a positive result even when you are not pregnant. There are some medications that can lead to false positives, including anti-anxiety, epilepsy, antipsychotic medications. If you are taking medication, it is best to read the patient information leaflet that comes within the pregnancy test packet which will tell you whether specific medications can have an effect on the pregnancy test result.

A ‘false negative’ is a negative result even when you are pregnant. This happens in around 5% of tests, and happens if you take the test too soon, or you have a faulty test. For best results, avoid taking the test too soon (wait until the first day of your missed period or if you’re not sure when your period is due, it is a good idea to wait at least three weeks after when you think you may have conceived).

Coping with the results – your next steps

Taking a pregnancy test can lead to many different emotions for different people; there are those who are desperately trying to conceive and those for whom parenthood is not the right personal choice. Remember if you fall in one of these categories, talk to your GP who can provide further support.

If you are pregnant, and this is a planned pregnancy, congratulations! After you’ve told your partner the big news, you will need to make an appointment with your GP so that they can register you with the maternity services and a plan for your pregnancy can subsequently be made. Although it may seem daunting, try to stay calm and relax; you can visit our section on pregnancy for further information.

If you are pregnant and it was not planned, our article “Breaking the News of an Unplanned Pregnancy” may help you consider what to do next.