There are three main cases of bleeding after taking the emergency contraceptive pill, and the causes of each case are different, and the treatment plan should be chosen according to the specific situation. First, withdrawal bleeding, which occurs about 1 week after taking the emergency contraceptive pill, the amount of bleeding is usually very small and clears in 3-5 days without any special discomfort, and this condition can be treated without any treatment. Second, consider bleeding due to abnormal pregnancy, such as preterm miscarriage or ectopic pregnancy. In this case, the patient needs dynamic observation of blood chorionic gonadotropin, progesterone and changes in the ultrasound to determine this. If the pregnancy is intrauterine, an early abortion is performed. If it is an ectopic pregnancy, pharmacological embryo-killing treatment or surgical treatment should be chosen according to the specific situation. Thirdly, irregular vaginal bleeding is considered, which is mainly caused by the endocrine disruption of the emergency contraceptive pill, the amount of bleeding is more or less, and the bleeding time is usually longer. Ultrasound should be done to observe the endometrial condition to choose the medication to stop the bleeding.