So I know this may sound stupid to some. But almost 2 weeks ago  I had sex with a guy, and he asked if I was on the pill and I said yes (because I am) but I had forgotten that I had forgot to take a few pills (about 3 or 4) and then the next day (or day after next I don't remember) I took the pills to catch up on what day it was... and since then I've have stomach and back pains. I took a pregnancy test a week after it happened but it was negative but of course I know those things could be wrong especially only being 7 days after... so I guess I'm wondering if it could be a possibility that I could be pregnant.?