Is a woman required to pray after fifteen days have passed from the onset of menstruation, knowing that the bleeding is still continuous and has the characteristics of menstruation?

The maximum period for menstruation is fifteen days. If the blood flow exceeds this duration, the woman is considered to be in a state of istihadah (definition) (non-menstrual bleeding), and the rulings pertaining to a woman in istihadah become applicable to her. It was not permissible for your husband to have intercourse with you before it became clear that you were in a state of istihadah. However, we hope that no obligation will be incumbent upon either of you due to the occurrence of intercourse, knowing that intercourse with a woman in a state of istihadah is permissible according to the preponderant opinion.