If a girl for the first time in her life or a woman who has remained pure for a minimum of 15 days since her last menstruation sees bleeding, she has to discontinue salat and fasting. If this bleeding terminates before 3 days are over, she should wait until it gets quite close to the end of the time for salat within which it stopped [she should wait until there is enough time for her to perform that salat before the time for it ends]. Then she makes wudu’ and performs it. If bleeding resumes, she must not perform salat. She should act likewise until 3 days are over. She does not have to take a ghusl because the bleeding may not be menstrual bleeding, so making only wudu’ suffices.
If bleeding stops after 3 days are over, she should wait until it gets quite close to the end of the time for salat within which it stopped. If she does not see any bleeding, she performs that salat by taking a ghusl first because it is certain that this bleeding is menstrual bleeding. But engaging in sexual intercourse is not halal, even though she has taken a ghusl. As long as blood flows, she should act likewise until 10 days are over. She takes a ghusl at the completion of day 10 and resumes salat. Because the blood flowing after day 10 will be considered istihada (non-menstrual bleeding), she will perform salat without having to take a ghusl. And it will be permissible for her to engage in sexual intercourse.