Is it permissible for a woman to perform ghusl after menstruation based on the usual number of her days without verifying the signs of purity, especially if the bleeding has stopped and the usual clear discharge has not appeared?

A woman recognizes purity by one of two signs: dryness (jufuf) or the white discharge (al-qassah al-bayda'). If she sees either of them, she has become pure and ghusl (ritual bath) becomes obligatory upon her. If the blood stops and she sees dryness, meaning the cloth is clean, then she has become pure and ghusl is incumbent upon her; she should not wait for other discharges. However, if she does not see purity or doubts its occurrence, the default is that menstruation persists. Performing ghusl after the cessation of the accustomed days without verifying the sight of purity is not sufficient, because the duration of the accustomed period may change. Whatever blood a woman sees is considered menses as long as it is within a time frame where it can be menses. Ghusl becomes obligatory as soon as purity is seen by one of its two signs, whether before or after the accustomed period. However, if blood, yellowish discharge (sufrah), or brownish discharge (kudrah) persists, she is not deemed pure until she sees one of the two signs of purity, even if it extends beyond her accustomed period, as long as it is within the time of menstruation.