The bleeding is not necessarily menstrual but may also be abnormal bleeding. If you have sexual intercourse without contraception, you should first rule out pregnancy as the cause of the abnormal bleeding. You need to use an early pregnancy test or come to the hospital for an HCG test to rule out pregnancy. If pregnancy is completely excluded and a small amount of bleeding occurs during non-menstrual period, it may be caused by ovulatory bleeding, endometrial polyps or submucosal fibroids, etc. You need to come to the hospital for ultrasound examination to exclude organic lesions and blood test for endocrine hormone six to see if there is any endocrine disorder, and then treated under the guidance of the doctor after a clear diagnosis. A small amount of bleeding a few days before menstruation may be caused by local endometrial breakthrough bleeding before menstruation, which can be observed for 7-10 days.