Q: My period is a week late but I have no pregnancy symptoms. I've done four tests, two of which showed positive, and two of which had only faint lines in the positive box. I then did a digital test that came back negative. Am I imagining it all?
A: A pregnancy test works by detecting the hormone human chorionic gonadotropin (hCG) that is secreted by the placenta.
Although a pregnancy test can be positive as early as the day your period is due, in the very early stages of pregnancy, the amount of the pregnancy hormone is very low so there is a greater chance of the pregnancy test reading as negative - known as a false negative result - even if you're pregnant.
It's vital to follow the instructions and to use a concentrated early-morning urine sample to give you the best chance of a test working properly.
If a pregnancy test is negative but you believe you are pregnant, see your GP who can arrange a blood test to confirm and exclude any complications that can result in a low level of hCG.
Only very occasionally can a pregnancy test read positive - a false positive result - when you're not pregnant. This is because the test has not been carried out properly, is out of date or is due to the effect of certain prescription medicines.