The normal duration of menstruation is 25-30 days, less than 25 days there is frequent menstruation and more than 35 days there is sporadic menstruation. If you have a period once every few months, it may lead to delayed ovulation and may affect the number of pregnancies, but it does not mean that it will affect fertility. First of all, it is necessary to exclude whether there are any endocrine hormonal diseases or some abnormalities of the uterus, and whether the scanty menstruation is caused by some external factors. It is recommended to check endocrine hormones on an empty stomach on the 2nd-5th day of menstruation to determine if there are any endocrine hormone disorders. Because there are some hyperprolactin and polycystic ovary syndrome, which may cause menstruation once in several months. If there are endometrial fibroids or endometrial hyperplasia, it may also cause delayed menstruation. It is recommended to have an ultrasound to determine whether the uterus is in normal form, and to take certain short-acting contraceptive pills orally to regulate the cycle and help restore menstruation to normal.