It is narrated from Hazrat Umm Salamah (may Allah be pleased with her) that once Hazrat Fatimah bint Hubaysh (may Allah be pleased with her) came to the service of the Prophet (peace and blessings be upon him) and said, "My blood keeps flowing continuously." The Prophet (peace and blessings be upon him) said, "That is not menstruation; it is blood from a vein. You should estimate the days of your menstruation and sit aside during those days. Then perform ghusl, tie a cloth, and offer prayers."