Hello! My son fell off the sofa ? I wasn't paying attention, he cried …

Hello! My son fell off the sofa ? I wasn't paying attention, he cried a lot, was scared himself. There are no bruises or scratches. Then he fell asleep, slept well. I am very worried and blame myself. I'm afraid he has a concussion ? Can you please tell me what I can do before we go to the doctor? He is very fussy, ? maybe something hurts him.