Could I get pregnant?

Soooo, this weekend I had sex my with my boyfriend. It was awesome just like usual but, this time he came on my back (which is normal) he kinda rubbed it into my back and then rubbed my vaginal hole, he never actually fully penetrated me. But anyways, We took a shower afterwards and I washed everywhere including my hoo-ha, just curious as if I should take plan B or if you guys think I’ll be okay.