Vaginal burning after sex, help!

I need advice! And just to cover my bases, I’ve had UTIs before. They usually take a little while to develop. I hadn’t seen my boyfriend in 10 days, we just had sex, definitely lubricated, no pain during sex, but the moment I sat down to pee right after, excruciating burning sensation.

We are monogamous, no STDs, and there was absolutely no pain before or during sex, and I was peeing just fine before.

Is anyone else just really sensitive to the potential germs on a guys penis, or semen itself? This happens a lot when I have unprotected sex. But when we use a condom, there’s no pain after. It may be a bacterial thing, but I’d like to think we’re pretty clean! I’m so confused. Please help! does this happen to anyone else?