No , no pregnancy....right?

Ok, so my period ended about Sunday and I'm on birth control and have never missed a pill at all. This morning, around 1 am, my boyfriend and I had "" with our clothes on...so technically, we didn't really have . He was in soft pj pants and I was in fleecey pj pants, and well, I guess you can say we just "grinded" and what not. He d, naturally, and after that, I felt something wet on my pants. I asked him if it soaked through and he said that he couldn't tell if it was that or if it was sweat. However, the wetness I felt on my pants could have very well been from me. I was just wondering that since it's about 4 days after my period, and his ejaculation may have gotten on my pants, is there any way I could be pregnant? I mean, we didn't have ...I'm still a virgin and it's not like I touched myself after the fact and he didn't touch me down there either. Should I worry? I've never missed a pill, like I said, and we didn't have ...