Retreat bleeding after taking the pill is the abnormal bleeding caused by irregular shedding of the endometrium due to the pill. Whether you take short-acting contraceptives or emergency contraceptives, there will be withdrawal bleeding, which may be a normal drug reaction, but may also be due to abnormal conditions.1. Normal situation: the pill is a hormonal drug, the higher the hormone content, the greater the chance of withdrawal bleeding. Retreat bleeding usually disappears on its own in about 3-7 days, this situation is a normal drug reaction. During this period, women should pay attention to keep their vulva clean and observe the amount of vaginal bleeding. It is recommended to visit the hospital for blood tests and ultrasound examination, and according to the results, symptomatic treatment, oral progesterone can be taken under the guidance of the doctor to stop the bleeding. If after taking the emergency contraceptive pill, the amount of withdrawal bleeding is small and no menstruation occurs by the time of normal menstruation, it is considered that it may be a contraceptive failure and it is recommended to do an early pregnancy test to rule out pregnancy or ectopic pregnancy.