Last month on the 20th of menstruation on the 5th of this month and blood may be ovulation, but also may be vaginitis, endometrial hyperplasia, cervicitis and other diseases lead to. 1. Ovulation: women in the first day of the next menstrual period about 14 days before the first day of ovulation, some women will have a small amount of vaginal bleeding and leukorrhea symptoms, so the patient will appear on the 20th of last month to menstruation on the 5th of this month and the phenomenon of blood. 2. Vaginitis: Vaginitis is caused by Chlamydia trachomatis, anaerobic bacteria and other pathogen infections, the main symptoms of patients are vaginal itching, pain during sexual intercourse, a small amount of vaginal bleeding. Therefore, the patient will also appear on the 20th of last month to menstruation on the 5th of this month and the performance of blood. 3. Endometrial hyperplasia: patients with endometrial hyperplasia will have abnormal uterine bleeding, prolonged menstruation, lower abdominal pain, etc., and will also have the symptom of having blood again on the 5th of the month after having menstruation on the 20th of last month. 4. Other: cervicitis, fibroids, cervical polyps and other diseases may also lead to the phenomenon of blood on the 5th of the month after the period on the 20th of the previous month. If the patient has the symptom of having blood again on the 5th of the month after the menstruation on the 20th of last month, it is recommended to consult a doctor in time to find out the cause of the disease and treat it under the doctor’s guidance.