Hi, So Yesterday I Had Sexual Inter Course With My

Hi, so yesterday I had sexual inter course with my boyfriend and we didnt used protection, he commented on my thigh and I wiped it off.. I took. Shower then I went to the bathroom everything was ok until today at school, I started feeling pain in my right side and I when I went to pee it hurt really bad, I think i might have an urinal infection.... When I go to pee a light pinkish/reddish color comes out when I wipe my private area and it hurts when I pee.
I would like to know what's going on and what can I do to stop the pain please