Normal menstrual period is 21-35 days. If your period is 7 days early and 7 days late, these are normal ranges and do not require treatment and have no effect on your body. If the period comes more than 7 days earlier, it is a menstrual disorder. It is necessary to do an ultrasound to see if the early onset of menstruation is due to the shortening of the luteal phase caused by poor follicular function. The normal luteal phase is more than 12 days, if it is less than 12 days, it is luteal insufficiency, that is, luteal atrophy, or premature luteal atrophy. Therefore, in this case, we should do ultrasound to see if the follicle is mature at the time of ovulation, and check the sex hormone six and thyroid hormone to see if it is caused by endocrine dysfunction.