Was what the questioner did two days ago, in performing ghusl and prayer, correct, taking into account the varying characteristics of the blood discharged, and must she perform ghusl again if she started menstruating today?

The maximum duration of menstruation is fifteen days. Any blood seen by a woman within this period is considered menses, and it does not become istihada (non-menstrual vaginal bleeding) unless the bleeding exceeds this duration. A woman should not rely on differentiation (of blood characteristics) or revert to her customary period if the bleeding increases beyond her habit, until it exceeds fifteen days. It is obligatory to wait and consider all the blood as menses until its total, including any interspersed days of purity, exceeds fifteen days. At that point, it becomes clear that she is mustahada. It is not permissible for a woman to act solely based on her own opinion in these matters; rather, she must consult trustworthy scholars and follow their rulings.