No chance. That is what the pill is for.
He also has to deposit his sperm pretty close to your cervix to have a chance to get you pregnant. Outside your panties is not even close. And then you are taking the pill as well, so once again, no chance.
If he did not pre-cum, he's got something wrong with him. The wetness on his penis when he gets aroused is pre-cum. I am yet to see a boy rubbing his erection on a girl's panties and not be aroused!!