Can I have a negative test and still be pregnant?

Pregnancy tests measure the level of pregnancy hormones in your urine. Pregnancy tests are very sensitive and a ‘false negative’ could happen if it is very early in the pregnancy as a pregnancy test take 3 weeks to show after sexual contact. In this situation your body may not have built up enough pregnancy hormone for the tests to detect yet. If you have any doubts, you can do a second test two or three days later.