Am I Pregnant? Im A College Student And I Was

Am I pregnant? Im a college student and i was at a bar and I met this guy and we were hooking up and my friends said they saw me walk towards the door with him but weren't sure if I actually left or not. I do not remember this happening as I was drunk. I never leave with guys and this is not something I would do. I am positive I did not go back to campus with him or to his room and I know we got pizza and I took a cab home. That is all I remember. I am paranoid that when I left with him we did not only have pizza but that we had sex somewhere and that I just don't remember. I don't know if I'm being irrational because my friends said I was missing for an hour and pizza is right around the corner from where I was and would not take an hour. I got my period 6 days after that night but it was not like my regular period it was extremely light and brown. It would pick up at random times. This really freaked me out as I thought I was sporting because my period never does this so I took a pregancy test that was negative. It's now almost 2 weeks since that night and I've been incredibly bloated and it feels like my metabolism has sped up because I'm eating more and having really bad cravings. I don't know if these things are happening from stress or another cause because I have been really paranoid and anxious about this also school is really stressful right now. What do you think?