Ectopic pregnancy and menstruation can be distinguished in the following ways: 1. whether menopause: ectopic pregnancy is caused by pregnancy and menstruation is a normal physiological phenomenon. most ectopic pregnancies have a brief history of menopause, while most menstruation is regular. 2. amount of bleeding: vaginal bleeding is less in ectopic pregnancy and more in menstruation. 3. doing a blood HCG test: ectopic pregnancy has an increased HCG value, while there is no change in HCG value when menstruation occurs. 4. 4. doing ultrasonography: the gestational sac may be seen outside the uterine cavity in ectopic pregnancy, and the separation of the uterine cavity can be seen during menstruation, but there are no abnormal changes outside the uterine cavity. By the above means, most ectopic pregnancies without miscarriage or rupture can be distinguished from menstruation.