What is the ruling on prayer when a brownish drop appears at the beginning of menstruation, then stops for a full day before the blood descends?

If a woman sees a brownish discharge (kudrah) during her menstrual period, it is considered menstruation. If she sees a drop of brownish discharge and then sees blood a day later, and the duration of both the blood and the brownish discharge exceeds a day and a night, then this entire period is considered menstruation. The woman must make up the prayers of the day that separated the brownish discharge and the blood, if she did not perform ghusl after the brownish discharge, because the intervening period of purity is valid.