Bleeding just after 15 days of menstruation is not necessarily pregnancy, it may be due to ovulation, endometrial polyps, cervical polyps and other reasons. 1. Ovulation: When bleeding occurs just after 15 days of menstruation, it may be ovulatory bleeding, which may be characterized by a small amount of vaginal bleeding, accompanied by slight pain in the lower abdomen, and usually lasts for 3 to 4 days. 2. Endometrial polyps: Bleeding between menstrual periods can be caused by the stimulation of the endometrium by polyp tissue, which can be diagnosed by ultrasonography and hysteroscopy. 3. Cervical polyps: they can also cause bleeding between menstrual periods and repeated contact bleeding, which can be diagnosed by ultrasonography and gynecological examination. If you have bleeding after 15 days of menstruation, you need to go to the hospital in time to find out the cause of the bleeding and actively treat it.