I went through about the same thing when I was your age. Doctor figured I was just growing, it's not uncommon for a male around your age to grow a little more.
If I could suggest anything to you it would be drink plenty of water, maybe some halibut or cod liver oil capsules for the joints, and just keep workin' and exercising and keep eating healthy.
BTW, do you do any aggressive mountain biking, dirt biking, or quading?
Those activities are actually what led to my pains, I did'nt grow at all