Is the blood seen by a wife after a 12-day period of purity, and after menstruation and an intermittent cessation that was preceded by taking pills to delay the period, considered menstruation? And does the ruling differ if the duration of the last blood is less than five days?

If the total duration of blood and the interspersing periods of purity exceeds fifteen days, and there was no period of purity lasting thirteen days within it, then she is considered to have Istihada (prolonged non-menstrual bleeding). In this case, she should refer to her previous habit, or apply the principle of differentiation: whatever bleeding possesses the characteristics of menstrual blood is considered menstruation, and whatever bleeding does not is considered Istihada.