OMG HELP

My boyfriend and I were hanging out and my sister took my mom shopping so the two of us were at my house alone. Things started off very heated. We were making out. I gave him a handjob, we thought someone was at my house. I told him we should stop. He said he wasn't gonna get blue balls. We continued and I rode him and we stopped because I was pretty sure my mom was gonna be home soon. He still had a boner but he didn't say anything to make me keep going. I don't think he came inside of me but how do I tell without asking him ????? I'm really nervous that I might get pregnant.