What Causes Fatigue And Diarrhea After Taking Plan B?

I'm 18 a college freshman female. I had sex for the first time 5 1/2 nights ago. He is 18 as well but so much more experienced and pretty rough too. Everything happened so incredibly fast and I'm not sure if he used a condom. So I got Plan B almost exactly 12 hrs after. Yes I had pain during intercourse and the expected pain the day after and light beeding. But the pain has continued for 5 1/2 days after and I have had heavy bleeding and the usual menstual cramps, kind of like my period. Also I have had pain while urinating really bad. So maybe UTI? But... I also have other symptoms that just started about 3 days ago. Extreme extreme fatigue, diarrhea, fever and I even had a dizzy spell and almost passed out. So what I'm sick is it just a coincedence that I'm sick? There is no way I'm pregnant right? Please help I really just don't feel good!