I’m probably freaking out over nothing

I started getting worried all of the time about getting pregnant so we agreed not to have sex until I get on birth control ( we always used condoms). He wanted to try anal a few weeks ago and I honestly was pretty down to try whatever. So we did it and it was pretty great honestly. But he pulled out and he came on my butt . And I’m just wondering if there is any real chance of becoming pregnant from cum like sliding down there or near there?😂 Pretty sure it didn’t since I was partially wearing underwear over the area. Just a question to make me stop worrying😂