Hard bump on roof of month

[steve12345]

I am a 27 year old male with who does not use tobacco. I beleive this bump has been there for years and gets irritated from time to time. It is as hard as bone to the touch and not painful. When I saw what it looked like I got worried. My denist never have mentioned it but I never brought it up because I was not worried until I saw it. Attached is a picture. Any idea what this? It is on the left side of the image.

could be.

 

[MattKW]

Can't see anything significant. Relax.