Positive Pregnancy

I just took a pregnancy test this morning and it came back positive. I have not had my period for about 5 months now, I didn't think it would be of any concern though... since my periods are irregular. On top of that my boyfriend and I are really careful when we have sex. I haven't had any signs or anything, but I was just wondering if UTI's could alter the test. I'm really worried now that I really could be pregnant. Please share your stories and advice with me. Thank you.