Some people will have ovulatory bleeding, which is also usually red in color. Ovulatory bleeding is caused by a decrease in the level of estrogen in the body during ovulation, which causes some of the endometrium to shed, resulting in a small amount of vaginal bleeding and an increase in vaginal discharge. Ovulatory bleeding is usually less than menstrual bleeding and lasts for 2-3 days before it ends. If the bleeding is bright red but in a small amount, and there are no other harmful signs, the patient can not worry about it and do a good job in observing their own hygiene. However, if the bleeding is black or in a large amount, the patient needs to pay attention to it and go to the hospital to determine the cause and treatment.