Doing a pregnancy test
Women often report that they had a sixth sense or “just knew” that they were pregnant. In fact, some
of the commonest signs and symptoms of pregnancy can be experienced quite early on following conception.
The earliest and most reliable indication of being pregnant is a missed period – this is particularly the case for women who have a regular 28-day menstrual cycle. This isn’t the case for every woman though, and some will have a shorter or much lighter period than usual. Consequently, they may not even be aware that they are pregnant.
The most accurate way of confirming a pregnancy is by doing a pregnancy test – this can be done from the first day of your missed period.
What does it check?
Pregnancy tests check for the presence of the pregnancy hormone ‘Human Chorionic Gonadotrophin’ (hCG) which is found in women’s urine. hCG starts to be produced around six days after fertilisation has occurred. If the pregnancy test is positive to the presence of hCG, this is normally a very accurate and reliable indication of pregnancy.
Some pregnancy tests are more sensitive than others and are designed to provide much earlier confirmation of a pregnancy – ie before the missed period. These more sensitive pregnancy tests may be able to detect low levels of hCG as early as four days before the period is due, or seven to eight days following conception.
How can I tell which test is best for me?
You can determine the sensitivity of the different pregnancy tests available by reading the information on their packaging. The sensitivity of pregnancy tests are clearly marked on their packaging – these are presented as mIU/ml (milli-international unit per millilitre).
Pregnancy tests generally range in sensitivity from 10mIU/ml up to 40 mlU/ml. Where the number falls into the lower range, this shows that the pregnancy test is more sensitive and is designed to detect the presence of hCG much earlier.
Negative pregnancy tests
It is important that you follow the directions that come with the pregnancy test. If the test isn’t carried out correctly or the test is taken too soon, it can show up as a negative result despite the woman being pregnant.
Studies show that one in 10 women who have a missed period, only have very low levels of hCG. This can also show as a negative result despite the woman being pregnant. It is therefore advised that where women experience a missed period but have a negative pregnancy test; they do a repeat pregnancy test three days after the initial test. This recommendation is based on the premise that if the woman is pregnant, the levels of hCG should be higher after a few more days and will give a positive pregnancy test the second time round.
What happens if my periods are irregular?
If you have irregular periods or a longer menstrual cycle, the earliest time that you can take a pregnancy test is 21 days after the last time that you had unprotected sexual intercourse. In some cases however, the pregnancy test will not show as positive until your period is at least one week late.
How do I do a pregnancy test at home?
Doing a home pregnancy test is very easy. They can be purchased over-the-counter from pharmacies/chemists and some of the larger supermarkets. Most pregnancy tests come in a box that contains one or two long sticks and easy-to-follow-instructions for their use.
To confirm whether or not you’re pregnant, you will need to pass urine (wee) on the stick – the result appears on the stick after a few minutes. You can do this by either passing urine in a pot and then dipping the stick into the urine afterwards, or by putting the stick into your urine stream while you’re having a wee.
All pregnancy tests are slightly different, so it’s very important that you always check the instructions that come with the packaging. It’s also important that you know how the test will tell you that you are or are not pregnant. Some tests will show a ‘blue’ or ‘pink’ line or a ‘plus’ symbol if you’re pregnant; while others give a digital result alongside lines, so that you know you’re definitely pregnant.
You should always check the expiry date on the packaging to ensure it’s still in date and will give you an accurate result.
When is the best time to do a pregnancy test?
You can take a pregnancy test at any time of the day, although it is generally considered better to do a test first thing in the morning. This is because the levels of hCG in your urine will be more concentrated at this time. If you do a pregnancy test in the morning it also means that you won’t have had lots to drink, which can dilute the levels of hCG in your urine.
Where else can I get a pregnancy test?
There are a number of places where you can get free-of-charge pregnancy tests. These include:
o Your local contraceptive/family planning clinic
o Sexual health or genitourinary medicine (GUM) clinics
o NHS Walk-In Centres
o Brook centres – these provide sexual health and contraceptive services for the under 25s
o Some GPs will also provide free pregnancy tests – check with your local Health Centre or GP Surgery.
NHS Choices. Doing a pregnancy test. Available at: http://www.nhs.uk/conditions/pregnancy-and-baby/pages/pregnancy-test.aspx [Accessed 3 August 2016].