A girl can get pregnant IF
spem enters the vagina, weather it be off fingers or whatever, there is only a chance of her getting pregnant IF
sperm enters the vagina within a few minutes of it being ejaculated.
Another note... I agree with
If you did not know the answer to this, then you are not ready for sex (of any kind).
but if you go ahead and do it anyway, use condoms, even for anal sex and oral sex, because STI's can be passed through those.
For more information read the "Safe Sex Advice" thread in relationships and dating.