Is it permissible to pray and fast when drops of blood appear three or four days after the end of menstruation, based on a doctor's consultation stating that it is an ovulation period?

The maximum duration for menstruation is fifteen days. If the spots of blood appear within this period, they are considered menstruation, and the woman must refrain from prayer and everything that is forbidden for a menstruating woman. However, if the total days of the first blood, the second blood, and the period of purity between them exceed fifteen days, then these spots are considered istihadah (non-menstrual bleeding). In this case, the woman must purify herself, perform ablution, and pray, and she is treated as one who is pure.