Is the intercourse that occurred after the cessation of bleeding and performing ghusl valid, or is the blood that appeared after intercourse considered menstruation?

There is no harm in a husband having intercourse with his wife after her bleeding has ceased and she has performed ghusl. The blood discharged after the completion of her regular period is not considered menstruation; rather, it is blood due to an ailment or dysfunction, unless it appears fifteen days after her period of purity, in which case it would be considered a new menstruation.