What is the ruling on a woman who experienced spotting for a week, then her menstrual bleeding started and continued for more than fifteen days, then she performed ghusl and her husband had intercourse with her, while her menstrual bleeding continued?

If the blood flow exceeds fifteen days, it is not considered a complete menstruation, because the maximum duration for menstruation, according to the majority of scholars, is fifteen days. In this case, you are considered to be in a state of istihadah (definition) (non-menstrual bleeding). The duration of your menstruation is what coincides with your usual cycle, or what can be distinguished by the characteristics of menstrual blood (color, smell,, pain). If you do not have a regular cycle or a distinguishing characteristic, then consider your menstruation to be six or seven days.

During the period of istihadah, you must perform ablution for each prayer after its time has begun. You may pray with it as many obligatory and supererogatory prayers as you wish until the time for that prayer ends. A woman in a state of istihadah is considered pure, so she is permitted to pray, fast, and engage in sexual intercourse. If your husband has intercourse with you during the period of istihadah, there is no sin or expiation.