2 y.o hit head on cement 2days ago. since then he's very irritable. still eating& drinking well. no other sx. he is getting molars. should i worry?

Other symptoms?: If he has had no vomiting, is walking, talking his usual ways, doesn't seem off balance, etc, i wouldn't worry too much. It could be his molars and there is a slim outside chance he has a slight concussion. If there was no loss of consciousness, and he seems to be acting his normal self except a bit crabby, would just continue to monitor. If this happened 2 days ago likely not a problem.