Cyst or bone chip?

Okay, So i came home from work today and see this little bubbly thingy on my left knee. It feels kind of solid, but not all the way. When I push my fingers on either side of it, it moves around, but Doesn't move on it's own, so it's not a bug or anything. It's this little bump on the top of my knee. I hear that it could be a cyst, but I did some research and it says they usually happen between ages 20-40, and I'm not 20 yet, and it says they usually happen on wrists and hands.... I talked to my parents about it.... I sprained my left knee rollerblading a couple years ago, and I also injured it in basketball... So I don't know if that could be a cause for a bone chip... but I will make sure someone checks it out at my next doctor appointment. But Does anyone have any ideas?
It could be a cyst (many types, likely sebaceous), ganglioma, Lipoma, etc in the soft tissues on top of the bone.

Its NOT a bone chip or related to the underlying bone because then it Wouldn't be mobile like how u are describing.

Cyst or bone chip? Keyword

Does anyone have any , Soft Tissue , Lipoma , Wouldn , I don , Doesn , now i , how u