I would doubt this would lead to pregnancy. First, there was limited sperm as you had not ejaculated. Don't get me wrong, pre ejaculate CAN impregnate a woman, however, you likely were covered enough during sex to make sure that didn't happen. Whatever pre ejaculate you had was inside that condom. You only lost the condom as you exited her vagina . . . so I would not be overly worried about this at all.