My 4 week old son fell today from the bed, ER says no CT scan possible, I need your recommendation?

My 4 week old son fell today from the bed while being fed. The height of my bed is roughly 60-70cm… Got a bump on his head exactly on the rear top right side… We took him to the ER where they kept him for observation for 4 hours by only doing physical examination for his body, head and checking his reflex… they ask me to keep an eye if he is vomiting or feeling sleepy etc… As an infant, they are always sleepy, however no vomiting at all… he only cry at the time of eating, but i feel is crying voice is more of pain rather than hunger… The attending told us he wouldn’t do a CT scan if it was his kid… I need your recommendation please… Thanks