Is it permissible for a woman to continue her fasting and prayer if she takes menstruation-stopping pills, then experiences pink discharge, which then stops?

The pink spots seen by the questioner after Maghrib prayer are not considered menstruation, do not necessitate ghusl (ritual bath), and do not prevent her from praying or fasting. This is because the minimum period for menstruation is one day and one night according to the Shafi'i and Hanbali schools. The Hanafis hold that the minimum is three days and nights, while the Malikis believe there is no minimum time limit for it. Accordingly, the questioner is pure, and the drops she saw, which did not continue to flow, are not considered menstruation by the majority of scholars.