Can i get pregnant if he has cum on his fingers and then puts them in me? what are the chances?

Yes but only if . . : You can get pregnant if he puts his sperm covered fingers inside you within a few days of you ovulating (this typically occurs 14d prior to next menses). Even withdrawal method is not suitable for birth control as men leak some lubrication fluid full of sperm even before ejaculation. That's why it's important for you to use some sort of contraception & for him to wear condom each & every time.