I normally have 26 day cycles. I started my cycle August 18, 2013. I had unprotected sex August 25, 2013. I took Plan B three hours later. I had what appeared to be a normal cycle September 9, 2013, it was just early. I had a negative pregnancy test result October 4, 2013 when I went to my doctor to be put on birth control. I haven t started the birth control because my period has not come. I am more than a week late. My question is if I am pregnant, could I have gotten pregnant on the August 25 incident and for whatever reason the tests were false negatives or would it have been after my suspected last cycle?