Okay...I know this is a little personal, but I have no one else I could ask and I'm hoping you can help me. Regardless of how dumb and ridiculous this sounds.
The other night my boyfriend and I were making out on a couch and he was laying down and he got a little excited and...did his thing. Is there any way I could get pregnant off of that? I was just wearing thin leggings and a T-shirt at the time and he had a pair of shorts on. Is it possible something could have happened?
Something happened alright, but it doesn't sound likely that semen got near your vagina.
You may want to consider a discussion with him about how to avoid high risk situations where pregnancy or sexually transmitted diseases can happen, or plan proactively to have protection (contraceptives, condoms). The Student Health Center is able to provide you with information about your options, or if you are not enrolled this quarter, the local Planned Parenthood clinic is available.