Did he cum in me???

So me and my guy had sex late last night/early morning and we went twice. The first round we used a condom and the second round we didn’t. We went a second time like 20 minutes after the first time. When we don’t use a condom he always pulls out and even though he does I still get a bit paranoid after the fact. Before he entered me, I made sure there was nothing on his penis, like precum or anything and there wasn’t. When he pulled out (sorry tmi ahead) I saw him jerking himself while releasing his cum out on my butt. When I went to clean myself up, it was a little wet down there but it usually is when we don’t use a condom, and I checked with my fingers and the wetness/fluid was clear and water like. Does it sound like everything is fine? I’m not sure how I would even tell if any cum got in me...but I asked him after if everything was straight with him pulling out and he said “100%”. I’m just debating whether I should buy a Plan B or Not.