pregnecy?

by the way we are or were virgins (I'm not sure)… okay my boyfriend (17) & I (16) tried to have sex (for the first time) but only the head of his dick would go in because of how I was position anyway he had a condom on but it was he's first time putting one on so i don't know if it was on right he didn't cum or anything but what is the chance on me getting pregnant ?