What is the meaning of the few drops of blood that precede menstruation, and how can they be considered connected to it, knowing that they may sometimes stop during the day before heavy bleeding, and should one stop praying and fasting upon their appearance?

If you do not see purity after observing these spots—meaning the cotton swab comes out stained with blood, yellowness, or turbidity—then these spots are menses because they are connected to the subsequent blood and there is no intervening period of purity. However, if the cotton swab comes out clean, then do not consider these spots as menses, and continue to pray until you see continuous blood; because the minimum duration of menses, according to the majority of scholars, is a day and a night.