What Are The Signs Of Concussion To Look For Post Heavy Fall?

I put my five month old boy stomach down in the middle of our large bed to brush my hair in the bathroom. It was only about less than 2 minutes when i heard a loud bang and my baby s wailing. I ran to him to find him face up on the hard floor crying. He fell off the bed about 24 inches high. It only took a couple minutes to calm him and get him smiling again. It has been about 34 hours since and hadn t found any bruises, bumps, or marks. His pupils are the same and dilate normally, i believe. He seems to be okay and hadn t called the doctor. Could it be possible that he could have a fracture or concussion that i don t know about even if he is not showing signs? The only different thing with him today is that he was extra fussy(though his first tooth is protruding), and when i stand him onto his legs he seems to want to drop them or bounce instead of standing still, but it could just be a new fun thing for him.I know this is alot to read but wanted to share all the details to get the best answer. -Thanks