During withdrawal bleeding, because of a small amount of bleeding, the endometrium will cause a small amount of shedding, and when shedding will stimulate the uterus to cause contractions, and this time will cause abdominal pain, which is caused by the uterine contractions. Usually the withdrawal bleeding will end in 3-7 days, and the amount of bleeding is similar to the first day of menstruation, or even near the end of menstruation, and in some cases it is even spotting bleeding. Withdrawal bleeding is caused by an adverse reaction to the medication and does not last too long. If it lasts too long for more than 7 days, it suggests that there are abnormal manifestations, first of all, it is recommended to go to the hospital and register with the gynecology department to do gynecological ultrasound to look at the situation in the uterus, to determine whether there is any unevenness in echogenicity of the uterine lining, and according to the results of the ultrasound, anti-inflammatory medicines and bleeding medicines can be prescribed to help the uterus to return to normal quickly.