When withdrawal bleeding is caused by oral emergency contraceptive pills, the withdrawal bleeding will usually end within 3-7 days and will not last too long. If it is more than seven days, it will indicate the occurrence of abnormalities. It is recommended to go to the hospital to register for an ultrasound in the gynecology department to see the condition of the endometrium, and according to the situation, anti-inflammatory and hemostatic treatment is needed, otherwise there will be infection and anemia for a long time. The amount of bleeding is similar to the first day of menstruation or even near the end of it, it will not be too much, if it is more than the amount of menstruation, it also suggests that there is an abnormality, and the same oral medication to stop bleeding should be taken while performing the examination. The emergency contraceptive pill is not 100% contraceptive, it will have a certain chance of failure, and the appearance of withdrawal bleeding does not mean that it is a successful contraceptive, it is best to try to buy an early pregnancy test about twelve days after intercourse to rule out the possibility of conception.