Hello, My Boyfriend And I Have Had Sex Several Times

Hello, My boyfriend and I have had sex several times before and we always use condoms. he also got tested for most of the common STD's. After sex sessions, I always make sure to urinate although the last time we had sex (last night), it hurt a lot the day after. It hurts to do normal stuff like sit down or run or even walk. My vagina stings a lot and itches and it hurts to urinate. I think I might have a UTI but I am scared that it is something more serious