2 year old chin implant doesn't feel stable - should I be concerned?

I had a chin implant done about 2 years ago and it's never really felt completely stable. If I push up on the sides I can feel it crunch and move slightly. If I rest my chin on my hand or any other surface at certain angles it also feels a little weak. It's not painful but I can feel an uncomfortable pressure at the front of my jaw when I do this. My surgeon did not use a screw to attach it to bone, but just placed it inside the periosteum. Is any of this concerning? Could it shift?