What does this mean? Any input would be appreciated.?

Ok, I've never really had a problem with this before but lately I've got the strange urge to like gnaw on something. Not just bite, but like use my molars and I've been gnawing on pens but I don't know if this is a symptom to something, or if I'm just strange. It's almost feels like my teeth need to feel the pressure of gnawing. Could this be a sign that my teeth are moving or some thing. I got my all my wisdom teeth removed about 2 or so years ago, also I'm only 17. I use to bite my nails a lot but that's kind of went away. Like I said any input would be appreciated.