I took regestrone 5mg tablets from 15th to 22nd March as I was on a vacation to delay my periods. Today is 26th and I still haven't got my periods. My due date was on 20th March but I usually have my periods each month at least 5 6 days late than the said date. Still not to take risk I took regestrone to ensure my periods don't fall during my vacation. But I am a little worried now as its 3 days since I stopped taking regestrone but I have still not got periods. What is the reason? I have had sexual intercourse during this period but we used condoms and checked that it didn't break plus my partner didn't ejaculate inside me while wearing condoms also.