What are the rulings concerning irregular menstruation, when should the sign of purity be monitored, and should prayer be delayed upon seeing brown discharge or thin streaks of blood before the onset of heavy bleeding?

If a woman sees blood, she is considered to be menstruating. When the bleeding stops and she sees purity, she must immediately perform ghusl (ritual bath) and pray without delay. Whether her customary period increases or decreases, all of it is considered menstruation as long as it does not exceed 15 days. If she sees yellowish or brownish discharge during her customary period, it is considered menstruation. She must check for purity when it is likely during prayer times, and she is not permitted to delay ghusl if she sees purity until the prayer time has passed.