Welcome to the club.

Go to your doctor and ask questions! (If the doc is under 40 yrs old, pulling out a little pocket notebook will probably get you bumped up a couple notches on his "respect" scale. There are a lot of people complaining of joint pains just to get special privileges at work or school, so one of the doc's unspoken questions will be "Is this guy trying to pull a fast one?".)

You will almost certainly be referred for imaging - x-ray, MRI, or ultrasound. Maybe all 3. In fact, if you're NOT referred, I'd ask "Why?". Call it "defensive diagnostics" if you wish but at the very least the imaging will rule out some pretty rare, but potentially very serious conditions. Things like bone cancer and ALS. Once the dreadful stuff has been eliminated, everybody can relax a little and put careful thought into diagnosing and treating your condition.

Regardless of what the final determination is, this is NOT something that should be ignored at your age.

Dale