Pregnancy Tests

Have you missed your period? Are there any other tell tale signs of pregnancy - tender breasts, nausea, or tiredness? If so, the chances are that you will not be capable of thinking about much else until you take a pregnancy test.

How do pregnancy tests work?

Home pregnancy tests work by measuring the level of a hormone in your urine known as hCG - hormone human chorionic gonadotrophin. This hormone is produced by the placenta and is usually present in your urine between 6 and 12 days after fertilisation. This means that it is possible to detect a pregnancy before the due date of your missed period, but the accuracy of home pregnancy tests increase significantly if used from the day of your missed period.

It is possible for a pregnancy test to be wrong, but this only usually occurs when a test shows a false negative, i.e. the test shows that you are not pregnant when in fact you are. The main reason for getting a false negative is that the levels of hCG are too low for the test to pick up on. A false positive result is very rare.

When can I take a pregnancy test?

There are a number of home pregnancy tests on the market that are marketed as early tests. These claim to be able to tell whether you are pregnant days in advance of the date your period is due. The reason that they can claim this is because they are more sensitive to hCG than standard tests, however, it is still possible for them to give a false negative result when used early. If you really want to be sure, then it is best to wait until the day your period is due, or even better, a week after that.

Being patient while waiting to find out whether you are pregnant is easier said than done. It is usually impossible to think of anything else until you know for sure. However, it is important to keep in mind that early miscarriage is much more likely during these early days and weeks. Many women miscarry before even realising that they are pregnant and for this reason, some people feel that early pregnancy tests cause unnecessary upset and disappointment.

How do I do a home pregnancy test?

It is important that you read the instructions enclosed with your pregnancy test because all brands vary in how to use and then read them. Some tests require you to urinate in a pot and then immerse the test into the pot for a given number of seconds. Other tests ask that you urinate directly onto the test stick.

When it comes to reading the test result, allow the correct amount of time for the result to show - this will be clearly stated in the instructions. The results are displayed differently across different brands. A positive result may appear as a line or a cross in a window, some give a digital reading of YES and others even suggest on a digital display how many weeks pregnant you are. Always cross check your test result with the instruction leaflet.

Which one should I buy?

Home pregnancy tests are widely available from chemists, supermarkets, online stores and even pound shops. There are a whole range of home pregnancy tests available for you to choose from, and they vary considerably in price. If you have irregular periods then you may find yourself buying tests quite regularly as you cannot rely on your body calendar to tell you when you are missing your period. While the expensive tests are aesthetically more appealing and usually easier or less messy to use, their cost can add up if you buy several. Cheaper pregnancy tests work in exactly the same way and won't leave you feeling guilty if you work your way through several in a few weeks.

What should I do if it is positive?

Congratulations! If you have done a pregnancy test and the result is positive then you are probably at least 4 weeks pregnant. You need to let your partner know that you are pregnant and then make an appointment to see your GP. Your GP will book you a dating scan around your 12th week of pregnancy - based on the date of your missed period. If you were not previously experiencing regular periods then there may be some question over how many weeks pregnant you are. In this case, your GP may book an earlier scan to establish a more accurate due date.