What is the ruling on my action after menstruation and bleeding continued for more than a month, where I considered the subsequent period a second menstruation after a temporary cessation, based on the calculation of the time duration?

If the duration of bleeding, along with any associated yellowish or brownish discharge, exceeds fifteen days, the woman is considered to be in a state of istihadah (non-menstrual bleeding). She should then revert to her previous habit and consider the excess as istihadah. If she does not have a habit, she should act based on a valid distinction: whatever is distinguished by the characteristics of menstrual blood is menses, and the rest is istihadah. If she has neither a habit nor a distinction, she should consider six or seven days of the month as menses and the rest as istihadah. If she sees purity for thirteen days or more, then any blood that returns thereafter is considered menses. However, any yellowish or brownish discharge that returns after this period is not considered menses.