7 year old new molars

[Woolyheads]

My 7 yr old is getting his first molars.
Twice over the last month he has experienced pain, bleeding from the gum and each time a tiny bit of tooth, or bone has come out and there is a hole.
He saw a dentist recently, but before this started.
I can find nothing online about the tiny tooth/bone fragments that come out.
Is this normal?
Has anyone else had this?
Last dentist appointment took 2 months to get, so hope for some reassurance from others in the meantime.

TIA

Is it the molars at the back? They call these grown up molars or 6 year molars or something like that. My daughter who is 6 has hers coming through. At the back and up the top. I read that once these are through they start losing their baby teeth at the front.