Does Spotting A Day Before Menstruation Nullify The Fast?
It is a matter of Ijtihaad, therefore the opinions are different. The ones who consider it the start of the menstruation cycle would say that the woman should not keep fast or say prayer and those who consider it not a part of or start of the menstruation cycle, they would allow to keep fast and say prayer. It is your discretion to consider it a start or not.