hi, I've been doing martial arts through my college for the past two years (chidokwan), I think it's awesome. I think you should definately go for it, it's good to try something new. And don't worry about falling behind, people are at all different levels and are training together. everyone was a beginner once. I find its an excellent stress reliever from homework and tests and the constant studying, and good exercise
Hope you find out what works for you.