Is it permissible to fast and pray during intermittent bloody discharge before the menstrual period, knowing that it is followed by the menses in its usual form?

This blood that precedes menstruation by days, if it can be considered menses (if thirteen days separate it from the previous menses, and its duration, along with the usual menstrual period and the period of purity, does not exceed fifteen days), then it is menses, and you must refrain from prayer and fasting during it. However, if it cannot be considered menses, then it is istihada (non-menstrual bleeding), and you should pray and fast normally.