During the middle of menstruation, i.e. ovulation, the endometrium loses its hormonal support due to a brief drop in estrogen levels, resulting in regular vaginal bleeding caused by partial shedding of the endometrium, called ovulatory bleeding. The vaginal bleeding may last for a few hours or 3 to 5 days, but rarely for more than 7 days, or until the next menstrual period. In some cases, the bleeding may be minimal, or may be in the form of blood in the band, and rarely reaches the volume of menstruation. The bleeding may be accompanied by discomfort, vague pain or pain on one side of the lower abdomen. The symptoms may occur continuously every month or once every other month, some people have it for several months in a year, and some people have it only once in a lifetime. A small amount of bleeding does not need to be treated and can also be treated with medication under the guidance of a doctor. How to determine whether ovulation is bleeding? 1. Measure the basal body temperature. It is a biphasic body temperature and bleeding occurs during the transition from low to high body temperature, which is the ovulation period. Ovulation test paper to determine the ovulation period. 2.Take blood to analyze the change of hormone level in the body. 3.Exclude other diseases that cause abnormal bleeding, such as cervical polyps and uterine fibroids.