I was taking norethisterone for 5 days to delay my period. On the 4th day of taking it I also had the nexplanon implant fitted. I had unprotected sex that same day, where no ejaculation happened within in the vagina. I bought the Ellaone morning after pill just to be safe. It's been a over a week now since I took the last norethisterone, and I still haven't had a period. I've taken pregnancy tests and they are all negative. Could the non show period be due to all of the hormones I have had in a short space of time?