How is that bragging? The stomach is the last place on the body to burn its fat reserves, at least in males. In females it's more thighs/hips. Getting a ripped stomach is really hard because it's not in our evolutionary/survival instincts to not have any fat reserves.
"I thought the maximum amount is 2-3 lbs a week? "
Absolutely incorrect. Nothing to worry about.
Tooth may hurt because you may be pressing/biting down harder than you realize when you are running.