Pregnancy can be clarified by a blood test for human chorionic gonadotropin in about a week, but abnormal pregnancies, such as ectopic pregnancies, cannot be ruled out by a test for hormone levels in the blood. It takes about a week after the formation of the fertilized egg for it to implant in the normal endometrium. It is only after implantation that human chorionic gonadotropin is secreted and checked in the blood. However, since the time of fertilization varies somewhat from woman to woman, there are differences in the values of the hormone levels checked by blood. The level of hormones in the body after pregnancy can reflect to some extent whether the pregnancy is proceeding normally or not, so regular hormone level reviews or ultrasounds are needed. In particular, pregnant women with hormone abnormalities in previous tests and those with vaginal bleeding or severe gastrointestinal reactions should take extra rest after pregnancy.