Question:
What is the ruling on a fasting woman who feels that her menses started before the time of breaking the fast, about ten minutes or in a period less than two hours? Is this day considered as a fasting day or do I have to make it up?
Fatwa:
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger. We ask Allah to exalt his mention as well as that of his family and all his companions.
If a woman does not have menses until after sunset even by one moment then her fasting is valid and she does not have to make up this day even if she feels that she has menses before this time. Feeling that you have menses without really having menses does not affect your fasting, unless you really have some blood discharges.
Allah Knows best.