Shaking

Okay so this guy that I have been talking to for the past couple weeks came over tonight and we had sex. I've been trying not too with him but he has been so patient and sweet like today he bought me a dozen red roses and lilies and a shirt/leggings and I've been emotional because my cousin was killed and the guy who killed him is going in for sentencing tomorrow so he stopped by to check on me. Anyways, we were on the floor talking and talking lead to making out and which lead to him eating me out which led to us having sex on the floor. The thing is though he's slept with over 100 girls (he told me) and I'm scared he might have something (everything looked normal but you can't always see stds) anyways so my question is we had sex for like 30 seconds or less but I was shaking it felt so good 😍 but can I have gotten an std? He didn't cum in me or anything because like I said it was 30 seconds or less and he stopped himself because he wanted it to be better but I just don't know if contact is enough to get something? I'm sorry I'm just really paranoid about stds because I literally don't know what I would do if I caught one. Sorry for the long post but any advice would be appreciated!!!