Unprotected sex... questions.

Me and my boyfriend had sex tonight, and it was unprotected, but before anyone freaks out I'll explain. We're both virgins and we just wanted to see what all the hype was about! He put it in for a few seconds and pulled right out. But yes technically it was unprotected. No semen though. And if there was pre-cum on his penis it wasn't in a big old glob because I didn't see or feel any at the time we put it in (so if there was some it was probably just spread around or something). Should I have worries? What are the chances of something going wrong? Never again, but what should I be concerned about right now? thanks so much