well me and my girlfriend was messing around a week after her period and i had got a little bit too excited and "came" in my uderwear..about two or three minutes later i took my underwear off and i dont know if it rubbed against her vagina...if it did can she get pregnant?
Very unlikely. Sperm can only live in air for a few minutes.
You have nothing to worry about. Sperm cells only live for a short amount of time. If it was dry, they're dead. Only way for a women to get prevent in this kind of situation is if you had ejaculated into her vagina and if the sperm and egg were in contact. No big problem