Took it to the next level

Soooo…my husband and I have been together for 13 years, married for 7 years. We just tried anal tonight for the first time!! It wasn’t as bad as I thought it would be, honestly. My question is, when we do it again is it okay if he cums inside me and not get prego? Two, any hygiene tips? I don’t want to poop on him. What happens if I do? Obviously if that happens the mood is over, but if not can we go from butt to vagina without any infections? Like hiv? Sorry I’m super new to this. Please no judgment.