hi there, young children can be quite dramatic and do not take their description at face value. Now what you need to do is keep a watch on him to see that he does not have any vomiting
or loss or consiousness or any dizziness
.If possible moniter his breathing and pulse which you can do by counting the number of breath per min at random when he is sleeping. If he is only complaining of pain and has no othr symptoms then you can let him be and give ibuprofen
and some soothing words and motherly love will make him feel better. If he does display any symptoms then take him to the ER and let a doctor examine him. Take care.