It is normal to have a period that clears in 8 days, because there is a clinical standard that it is abnormal if the period lasts more than 9 days. If your period usually clears in 4 days, but this time it clears in 8 days, it may be due to a pathological cause. It is recommended to go to the hospital as soon as possible to have the appropriate tests to understand the cause and if necessary, treatment. The causes of long menstrual periods may be endometrial inflammation, endometrial polyps, endometrial atypical hyperplasia, or submucosal fibroids, large interstitial fibroids, ovarian tumors, endometriosis, etc., all of which may lead to prolonged menstruation, so be actively examined and treated according to the results.