Sensitive pregnancy test strips are adjusted to detect hCG in urine sample at concentration exceeding 10 mIU/ml. Thus, they detect pregnancy 2-3 days earlier than the expected beginning day of menses. However, interruptions of pregnancies occur mostly at very early stages. Might positive result of sensitive pregnancy test be followed by menses, the reason is more likely interrupted pregnancy than a false positive result. Sensitive pregnancy tests are favoured by women who need to change medication due to pregnancy.