I normally have 28 cycle of each months for a long time. until last month of Jan, i had a real bad mirgaines for a week, went to the dr to help me with my headaches. she gave me the prescription to help me with the mirgaines. I took the capsules for almost 1 week and half. I felt much better, then i stopped using those prescription. As of this month, on 28th day and i was excepted to get my period but never came. So i thought i would have been pregnant since we re trying for 4 months. but until on 3rd day of missed period, finally got my period start... then i realized that my period has been in 31 days cycle. made me wondering why its so late. then i realized that maybe the prescription that i took last month does effect to my period or no? let me know. the name of prescription i took was isometh/apapdichlor. help will be greatly apperciate. thanks.