Do I have a UTI or something?? Help!?

When I have sex with my boyfriend I feel great, but afterwards I constantly have to pee for like 24 hours straight and it kinda hurts. It’s not like burning or anything though, I don’t really know how to describe it. It’s been happening for a while and I just recently went on birth control (the shot). My doctor has taken urine samples and nothing has come back, does that mean that I’m fine or can there still be a possibility?