Belly Button Piercing? Help?

I got my belly button pierced April of 2010. And I don't think it's healed completely yet. It's not infected or anything. It can be a little red around the top sometimes, but no pain, or bleeding or puss or anything like that. So it's not infected but it's not healing haha Does anyone know why it won't heal? i want to change the jewelry, but not if it's not healed.