My last cycle was from May 4th-9th. I had sexual intercourse on the 14th, and also took Next Choice EC the next day. I got (what I believe to be) breakthrough bleeding from the 20th-25th. I then had sex (pull-out method) on June 1st. I took 2 pregnancy tests: one on June 2nd (negative) and another on the 7th (negative). I expected my period around the 5th of June, but feel more sick to my stomach and tired all the time instead of PMS. Is there chance of pregnancy, or late period do to BTB?