It is normal for women to have their period for 7 days. Most women have their period for 3-7 days, as long as it is within this range, it is normal. If your period lasts longer than 7 days, it is considered to be too long. The duration of menstruation is related to the thickness of the lining and hormone levels. If a woman’s lining is thicker and her hormone levels are not particularly stable, the duration of her period may be prolonged. If a woman has an IUD or fibroids, her period may also take a little longer to arrive. As long as the menstrual period is within one week and the volume of menstruation does not exceed the normal range, it will not affect pregnancy and regular gynecological examination is recommended.