This is stupid bit question

So me and my boyfriend went to the beach and we were messing around and he was behind me we were kinda grinding under water and he got hard and came so I was curious is it possible for me to get pregnant like that ? (stupid I know I’m just anxious) there was no penetration and he was by my butt but is it possible? Like I don’t think so cause it would have to get through his shorts swim through the water and into my Vagina but idk just a dumb question.