It was narrated from ‘Amr bin Az-Zubair that Fatimah bint Abi Hubaish told him that she came to the Messenger of Allah صلی اللہ علیہ وآلہ وسلم and complained to him about (continual) bleeding. The Messenger of Allah صلی اللہ علیہ وآلہ وسلم said to her: “That is a vein. Look and when your period comes, do not pray, and when your period ends, then purify yourself and pray during the time between one period and the next.” (Hasan)