This is not a thing you can diagnose or treat.
Go to an ENT specialist
and get your Oral cavity and Pharynx checked by endoscopy
If there is a bone then it could be dangerous if it goes down and gets stuck up somewhere in food pipe.
See normally when we eat non vegetarian food the bone traumatizes the skin inside mouth and goes down or we spit it.But due to trauma there is pain and false feeling of bone piece in mouth.
But in your case if you have really seen the bone piece then you must go to doctor and get it removed before it goes down.
If you have not seen but just the feeling then ,,then also go to doctor and get yourself examined and you can take this---
+Domperidom two times a day half an hour before meals
gel 2 tsf two times a day half an hour before meals