A period that has just passed and comes back a few days later is abnormal uterine bleeding. There are many causes of abnormal uterine bleeding, such as endocrine disorders, gynecological diseases, and ovulatory bleeding, as follows: 1. Endocrine disorders: Endocrine disorders can cause abnormal uterine bleeding. 2. Gynecological diseases: Such as cervical polyps, cervical erosion, or endometrial polyps, endometrial hyperplasia, and endometritis can cause menstrual disorders. 3. Ovulatory bleeding: Ovulatory bleeding also occurs in The menstrual period has just passed a few days and then there is an onset of menstruation. If it is an occasional occurrence of menstruation just past and again, and the amount is not much, you can temporarily observe. If there is no such situation next time, you can temporarily withhold treatment, but if there is often a case of menstruation just past a few days and again, it is still recommended to go to the hospital in time for the relevant examination, according to the examination results of symptomatic treatment.