Pregnancy tests usually involve weeing on a small plastic stick, or sometimes, weeing into a cup and dipping in a test stick. The test is looking for the hormone human chorionic gonadotrophin (HCG) which is present in the wee of someone who is pregnant. It takes a while for this hormone to build up in the body so there is no point doing a pregnancy test straight after unprotected sex. If you’re worried about the risk of pregnancy at this point, it’s advisable to use emergency contraception. This will work up to five days after unprotected sex. To get an accurate result it’s best to test three weeks (or 21 days) after unprotected sex or straight after your period should have been due (whichever is sooner), if you test before this time there may not be enough of the pregnancy hormone to show up in your urine.
A negative result means you probably aren’t pregnant but it could also be that the hormone is not yet detectable. If the test is negative, but your period doesn’t happen when you expect it to, it’s recommended that you take another pregnancy test, and this is usually done a week after the first test. You may also find it useful to visit a clinic to speak to a doctor or nurse about the test result, or if you are worried. This might also be a good time to talk to someone about contraception, if you weren’t trying to get pregnant.
