I took a birth control injection and my menstruation stopped for a month. Then, in the following month, it came five days earlier than its usual time, lightly and with a clotted consistency, knowing that it usually comes one or two days before its time. I ask whether this is menstruation or istihadah.

The blood that appears five days before the period is considered menstruation if it continues for a day and a night and occurs at a time suitable for menstruation. If it stops before a day and a night, it is not considered menstruation according to the majority of scholars. The blood a woman sees outside her usual time is considered menstruation as long as it is at a time suitable for menstruation. It is not considered Istihadah (definition) (non-menstrual bleeding) unless it appears at a time unsuitable for menstruation.