A 13-year-old girl has two menstrual periods in a month. This condition is due to the fact that the child is too young, in the early stage of development, the pituitary-ovarian axis is not fully established, no regular menstrual cycle has been formed, the hormone level in the body shows fluctuations and no cyclical changes, so she has two menstrual periods in a month, and one is considered to be ovulatory bleeding. Ovulatory bleeding, usually one time is a small amount, this situation is considered in the second half of the menstrual cycle, under the guidance of the doctor, the application of progesterone to regulate menstruation to stop bleeding treatment, usually the treatment should be about 10 consecutive days, continuous treatment for 3 menstrual cycles, under normal circumstances, the girl’s menstruation can be restored up. There is also a possibility that two menstrual periods must cause more blood loss, which can cause secondary anemia in girls, so it is necessary to do routine blood tests, timely supplementation of iron and correction of anemia treatment.