Ok this is embarassing to ask, but can you get a infection from a letting your dog lick your vagina?

Probably not: As you might imagine, there has been no research on this. But it's probably safe from an infection standpoint. Cunnilingus (oral-vaginal contact) among people very rarely transmits STDs, and dogs don't carry STDs. That said, cunnilingus may predispose some women to bacterial vaginosis. I doubt this sort of contact would to that, but nobody knows for sure.