My bf masturbated and he has a semen on his hand. he wiped it using wet wipes, we're not sure if he got it all since it's microscopic. after a few min. he fingers me, which means it's already exposed to air. can i still get pregnant? i'm scared?

Pregnancy is not possible in above circumstances. Contraception remains otherwise key in avoiding undesired pregnancy and associated anxiety, specifically when intercourse becomes possible.

It all depends whether he wiped it all out and when he used his fingers. From your description the chances are close to 0 bot not 0.. Pl be more careful next time.