Can you get pregnant if he pulls out cums on your tummy then goes back in without wiping off on a towel?

Ok so here is the deal. Me and my boyfriend have had sex a few times, but because i am allergic to latex we dont use condoms. Recently we had sex and he pulled out and came on my stomach, but when he felt he was done he went back in without wiping his penis off on a towel. I am kinda worrying now could i be pregnant?