What are yellow and turbid discharges, and when are they considered menstruation or postpartum bleeding, especially when one cannot precisely recall the days of one's regular period?

"The characteristics and rulings concerning yellowish and brownish discharges have been explained in previous fatwas. The fatwa (definition) adopted by us is that yellowish and brownish discharges are not considered menstruation unless they occur during the period of one's regular cycle or if they are continuous with blood. If you do not have a known regular cycle, then according to the apparent and adopted position of the Hanbali school of thought, yellowish and brownish discharges are not considered menstruation, whereas the majority of scholars hold that they are considered menstruation if they occur within the possible time frame of a menstrual period."