You don't say just how young you are, but its not uncommon for joints to crack or pop with movement. Were you X-rayed or scanned for arthritis at all? If so the doctors should have been able to tell you categorically if you have any signs of early arthritis.
You could try taking some dietary supplements, i.e. Glucosamine Hydrochloride. I started taking these when I first found out I had arthritis, and they certainly reduced the pain and stiffness in my knuckles, wrists and ankles. They are not a drug, so you can take them safely and they are available on the internet.