I'm 21 years old and have been working at UPS for the past 7 months. Recently I've developed what look like Heberden's nodes on the last knuckle of my index/middle finger on both hands. I don't know for sure if that's what it is, but it sure looks like it.

Are these nodes a warning of osteoarthritis developing? Should I see a doctor about it? What other explanations are there for a single bump appearing on the top knuckles?