STD? Pregnant? Birth control? Help?

11 days ago me and my boyfriend had COMPLETELY protected sex (first time having sex for the both of us). I'm on birth control, he wore a condom, and he didn't ejaculate. I'm worried I could be pregnant because we had sex while I was having breakthrough bleeding. This morning I woke up nauseous, and have been all day, and it only subsides when I eat. My breast hurt but I have Fibrocystic Breast Condition. About the STD's - I have been with my boyfriend for a year now and I'm sure he doesn't have any STD's. I quit having the breakthrough bleeding today for the first time in 2 weeks. But then I noticed it felt like I had started my period and well and behold there was a little but of brown spotting in my underwear. Also my vulva/labia were irritated for a few days.. but that stopped and the redness is going away now that I have stopped wearing sanitary pads. It doesn't burn when I pee, and I did not start itching until I read online that Yeast Infections involve itching -_- (i'm quite the hypochondriac). I'm wondering if I just have UTI because I didn't pee after intercourse and the upset stomach is the same stomach bug my mother and cousin have.