How does a woman determine when to start praying after menstruation, and what should she do if she prays and then sees blood or a brownish discharge?

A woman's purity from menstruation is achieved by the cessation of blood flow. Purity is recognized by one of two signs: the discharge of "al-qassah al-bayda'" (white discharge), which is a white fluid, or "complete dryness," which means that a cotton swab inserted comes out clean. Menstrual blood is distinguished by its black color, thickness, and unpleasant odor. It differs from istihadha (non-menstrual vaginal bleeding), which is red, thin, and odorless. Menstrual blood prohibits prayer, whereas istihadha blood does not prohibit it, with the reservation that one must perform ablution for each prayer. Yellowish or brownish discharge (sufra and kudrah) after purity is not considered menstruation and does not necessitate ghusl (definition) (ritual bathing); rather, it only necessitates wudu (ablution). However, if it is connected to menstruation, then it is considered part of it. If blood returns after one believed herself to be pure, it is considered menstruation unless it continues for most of the month.