Is the wife still bound to her husband because of the intercourse that occurred during her waiting period after she was thrice divorced while menstruating?

Divorce pronounced during menstruation is valid according to the majority of jurists. Repeating the word "divorced" three times could result in three divorces if the husband intended them, or a single divorce if he intended emphasis or had no specific intention. Resumption of marital relations (ruju') is valid either by agreement or by cohabitation. If the husband denies the resumption, evidence is required to prove it. It is best to refer matters of dispute to the Sharia court.