Weird bumb for years...

To the left of my right hip bone and down a bit I hav a bump. Its movable with my finger and when I lay on my stomach its used to be noticeable (I was anorexic so every bump n bone showed sadly). Fast forward a few years, I totally forgot about it then felt it again today. Its on my left side too. It feels like its attached to something. Any clues what it could be?