My Son Is 11 And On Thursday We Was Accidentally

My son is 11 and on Thursday we was accidentally punched in the face, slapped and then fell hitting his chin on the concrete. Following this he felt dizzy and sick for several hours (but wasn't sick). He spent that day and the following day talking slightly differently as his jaw was sore. By Saturday he was able to speak properly but it still saying it hurts when he eats and is unable to play his tenor horn at all. He has faint bruising under his eyes. We have assumed that he bruised the bone but given it is still sore over 3 days should he be chekced out by a GP?