Me and my girlfriend had sex with a condom on and when we got done there was whit stuff on the bottom of her vigina. Could it be sperm or something else. Could she be pregnant

Sounds like the condom broke, zackary. Do you not know what sperm looks like? Its usually white, but yes, she could be pregnant if the condom broke and you two better get educated if you are going to be sexually active. You sound young. It doesn't take much sperm and it doesn't have to be completely inside to be productive, in this instance, impregnated.

Tick

The condom may not have broke. Women produce sexual fluids during intercourse and even "ejaculate" during climax. This mixture of fluids produced by the women are used to help transport sperm to aid in reproduction.
Don't get me wrong, yes, the condom could have broke and what you could have seen was semen, but the fluids release by a woman are similar.