Bubble after dry socket

It's been about a month now since I have had two of my wisdom teeth extracted. I also have had a dry socket, But after I had this dry socket taken care of I began to notice a bubble forming about one week after I seen the dentist that took take care of my dry socket. It's now been a total of a month and this bubble is still there and it does not hurt or give me pain at all, but today there was something sharp poking out of this bubble, so i took some tweezers and removed it. It was a fragment of something hard/round with a sharp point. Should I be concerned about this bubble that is still there and what could that fragment have been?