OK, I might sound weird right now...
In my opinion, if you are at school, don't get into it, or at least try not to. My ex and I almost had full-on sex on many occassions and when my cycle came late, we both freaked out to a point of me having panic attacks. DON'T have sex. Bad idea. Enough said. Light touches are ok, but only if you two are confortable with it. If not, lay off.