UTI or??

My boyfriend and I had sex yesterday and he came inside me once, I tried to clean up as much as I could but I had to leave soon after, so there was some left whenever I got home and could finally clean up more.

I’ve heard that not cleaning up can cause issues, but wasn’t sure exactly what.

Today, I really really had to pee and when I finally went to the bathroom, I barely even let any out. Then like 10 minutes later, I still felt like I needed to pee really bad. Went again, and only a couple drops. I hate the feeling, it’s so annoying.

What could cause this?