After pregnancy, human chorionic gonadotropin is mainly secreted by gestational trophoblasts. As HCG doubles every other day with the increase of gestational weeks, the value of HCG varies greatly with different time of menopause. For women who usually have regular menstrual cycles, the normal value of HCG is usually more than 100 U/L at about 30 days after menopause, and it is normal for HCG values to be more than 2000 U/L at about 40 days after menopause. For women with irregular menstrual cycles, there is no way to determine the exact time of ovulation, so it is necessary to review the HCG every other day, as long as the HCG can be doubled, it is often a normal phenomenon.