Could i be pregnant with 4 negative test

So I got my period like i was supposed to and I take BC pills. I had sex before i went on a trip not protected. i went out of state and while gone i took my pills the first day but then i forgot to take it for 2 days and also was taking it at a 2 hour time difference. So i thought nothing of it cuz whatever but then I get home and the week after I got my period AGAIN for the 2nd time in less than 2 weeks. So when it came to the time to get my period again I didnt. So 2 weeks ago (which was 3 weeks late from my period) I took a pregnancy test twice, in the morning on monday and in the morning on Wednesday, and they both came negative. And now im 2 months from the last time I got my period and so I took a test yesterday morning and then this morning and both of them are negative. My stomach hurts alot and i feel like im bloated. Could I be pregnant still? Otherwise I have been under alot of stress lately too because of college finals so could that be it maybe?