When vaginal bleeding occurs after taking the emergency contraceptive pill, the following four conditions are mainly considered: First, withdrawal bleeding. If a small amount of vaginal bleeding occurs after taking the emergency contraceptive pill for about a week or so, the main consideration is withdrawal bleeding because the emergency contraceptive pill is a highly effective progestin, so when its metabolism is over, the hormones in the body will fluctuate, thus causing withdrawal bleeding. Second, to consider the onset of menstruation. After taking the emergency contraceptive pill, if the time of vaginal bleeding coincides with the menstrual cycle, consider that menstruation will come. Third, to consider pre-miscarriage or ectopic pregnancy. If, after taking the emergency contraceptive pill, the patient has vaginal bleeding, the amount of bleeding is relatively small and accompanied by abdominal pain, it should be highly suspected of ectopic pregnancy or pre-eclampsia. Fourth, to consider bleeding caused by, for example, bleeding during intercourse, ovulation bleeding, gynecological inflammation bleeding, etc., although it occurs after taking emergency contraceptive pills, but it is not related to emergency contraceptive pills.