HE CAME IN MY BUTT!!!

So I need help. Monday me and my boyfriend had sex without a condom. Usually when he’s ready to cum he will pull out and do it on my buttcheek of somewhere that’s nowhere near my vagina because I do not want to take any chances....but Monday he came in/around my actual butthole. I’m neevous that maybe something slipped and went inside me. Does anyone know any ways to make sure I’m clean or to prevent getting pregnant at this point? I feel like I should be ok I’m just paranoid!!! Please help!!!!🤷🏽‍♀️😓😭💙