Is it permissible to fast and engage in sexual intercourse for one whose menstruation began on the first of Ramadan and continued for five days, then stopped, and then the bleeding returned on the seventh day and is ongoing?

If the bleeding returns and the total of its days, along with the days of the previous bleeding and the period of purity between them, does not exceed fifteen days, then it is menstrual blood (hayd). If it exceeds fifteen days, then you are experiencing abnormal uterine bleeding (istihadah). In this case, you should distinguish between the blood based on its characteristics. If you cannot distinguish, or if the condition for distinction is not met, then you should refer to your known regular period. If you do not have a regular period, then consider yourself to be in hayd for the predominant duration of menstruation, which is six or seven days. It is preferable to consider the situation of your female relatives. Menstruation prohibits prayer, fasting, and sexual intercourse. A woman experiencing istihadah is considered to be in the state of purity.