We had a chick hatch last night which has a little bubble at the bottom of his tummy. Is this something to be converned about or will it sort itself out?
That's unabsorbed yolk. It's only small so it's likely the chick will finish absorbing the yolk shortly and the navel will close fully after that.
I'd put some antiseptic cream on it to help prevent infection and watch out for other chicks pecking at it. If they do, you might need to separate this one temporarily, or you could try making some sort of body stocking for the chick to keep it (loosely) covered - something like a cut down child's sock might work.