Biochemical pregnancy refers to a pregnancy in which the fertilized egg fails to implant and is expelled from the body with menstruation. Test strips may show weak positives in early stages of biochemical pregnancy and negatives in later stages. Chorionic gonadotropin is secreted about seven days after the sperm and egg unite, and it takes another seven days before it can be detected on a test strip. In the early stages of a biochemical pregnancy, hormone levels gradually decrease, at which point it may show a weakly positive result on a test strip. However, as the biochemical pregnancy is expelled with menstruation, the human chorionic gonadotropin gradually returns to zero and the test strip will show a negative result. After the sperm and egg unite to form a fertilized egg, if it does not attach successfully, it will lead to a miscarriage, i.e., a biochemical pregnancy. After a miscarriage in a biochemical pregnancy, menstruation will occur. Generally, biochemical pregnancy does not require special treatment, but if severe abdominal pain, dizziness and shock occurs, it is necessary to go to the hospital in time.