What should a woman whose menstrual cycle has become irregular and who does not remember her regular habit do, when she believes it was seven days?

The fatwa has settled on the ruling that any blood seen by a woman during a period when it could be menstruation is considered menstruation, because the regular period can change. This is the view preferred by the verified scholars of the Hanbali school, and it is more convenient for women. Based on this, the blood is considered menstrual unless it exceeds fifteen days.