Is malodorous blood that appeared less than 15 days after purification, and is considered a side effect of birth control pills used to treat polycystic ovaries, menstrual blood or istihada (non-menstrual vaginal bleeding)?

Drops of blood are not considered menses unless they are connected to flowing blood, because menstruation is flowing blood. The minimum period of purity (ṭuhr) between two menstrual cycles is thirteen days. The preponderant opinion is that any blood discharged is originally menstrual blood, unless it exceeds most of the month. However, this applies to flowing blood, not to drops. Light blood or scant drops that persist with a woman are not considered menstruation; rather, they originate from veins and do not prevent her from fasting or praying.