It was narrated that 'Aishah said:"Fatimah bint Abi Hubaish came to the Prophet: 'O Messenger of Allah! I am a woman who bleeds continuously and never becomes pure. Should I give up prayer?' he said: 'No, that is just a vein and is not menstruation. Do not perform prayer during the days of your period, then take a bath, and perform ablution for each prayer, even if drops of blood fall on the mat

English translation · Sunan Ibn Majah