Hi. How does he "think" he pulled out in time? Did he ejaculate after pulling out, or before? It's pretty simple... Secondly, yes. During any time in your cycle, you may become pregnant. Typically, women ovulate 14 days before their period, but that's never an absolute.
All you can do at this point is wait until your next period, about 4 weeks from now. Then, take a pregnancy test if your period misses or isn't much beyond spotting.
If you are pregnant, there are three options. Abortion, keeping the baby, or giving it up for adoption. You're far from worrying about that right now however.
I wish I could comfort you and say it's unlikely that you're pregnant... Most women don't ovulate so soon after their period but there's just no way to know.
Once you've confirmed whether or not you're pregnant, then you can get on some birth control. It can be free if you're a student, and your parents don't have to know.