Pregnancy scare because of ocd

I'm using a throwaway account for this because it's really embarrassing but i dont know where else to go. Basically I'm having a really bad ocd flare up because im thinking I got pregnant after sitting on a toilet seat. I was at someone else's house and I had to change my pad and I ended up sitting back down on the toilet and my pad and underwear ended up touching the top of the toilet seat. I got scared that somehow someone in the house had gotten semen on the seat at some point and now it was in me. I've been extremely paranoid all day about this. I had changed my pad again and I felt like I had touched items from earlier that were contaminated before this and so I thought I'd take a shower to "wash away anything bad", it usually helps me with any kind of anxiety I'm having but when I went in to the shower I ended up having an even worse panic attack, scared that if I washed anywhere down south it would somehow make it guaranteed I'd be pregnant so I got out of the shower and now I'm in a kind of limbo where I'm still scared I'm going to get pregnant but the only way for me to feel any better is also going to make it 10 times worse. On top of that most of my body everywhere else feels contaminated too with semen. I know this was an extremely long post but in the case anyone has any suggestions for this I'd really appreciate it as I don't have any other resources to go to at the moment and this is very much a last resort situation.