[Fjoergyn]

So, I went to my second ever Jiu Jitsu class the other day, and needless to say I practiced arm bars for the majority of the session. The thing is though, a lot of times I went to extend the arm I ended up crushing my balls, and today I have a bruised pelvis. Am I doing them wrong or is this a normal experience? I have compression shorts and can put a cup in there, but would that affect my training?