Help!!

Okay, so my boyfriend and I are very sexually active (we have sex almost everytime we see eachother) I am not on any form of birth control but we never have sex without a condom. Tonight we did and he was pulling out to switch to another position (not because he came) but the condom came off. In me, then slid on my thigh. I asked him if he came and he said no, but I'm extremely worried about pre cum. I asked him if I should take the day after pill and he told me he thinks that he didn't pre cum yet and I don't need to take the pill.