My last period was on march 27-30 2014. And my bf and I had our intercourse last April 16-19 2014 (we were out of town so we did it for 4days straight) but he withdraws all .He never put it inside of me but I'm still concerned that I might get pregnant.So I decided to take nordette today (as of 6pm Sunday). It is still effective ? and when will I expect for my period to come? thanks A lot .