Is blood discharged after a delayed and unusually prolonged menstrual period considered istihadah (non-menstrual vaginal bleeding) that necessitates ghusl (ritual purification bath) and performing Hajj rituals?

If a woman miscarries a fetus that is less than 81 days old, the blood discharged is not considered nifas (postpartum bleeding). If it coincides with the time of her menstruation, then it is menstrual blood; otherwise, it is istihada (irregular vaginal bleeding). Istihada blood does not prevent prayer, fasting, or circumambulation (Tawaf), but ablution (Wudu') is required for each prayer. The default rule for discharged blood is that it is menstrual blood, unless it exceeds fifteen days.