Also concerning Menses:

lIf a woman's menses ends during the night and she does not take the ghusl before time to begin fasting, she simply take the ghusl when she wakes up and her fasting is valid lIf a woman believes her period will begin tomorrow, she must continue to keep her intention to fast until she actually sees the blood lIt is best to avoid medication to stop your period and instead accept the concessions of Allah