Child Got Hit On The Head After The Surgery For Infected Cyst Removal, Felt Sleepy After The Incident. Emergency?

My son who is 2 years an a half has hit his head twice in on week (4 day aparts) one in forehead left side and one in right side of his head; right above a surgery he had to removed an infected cyst (:thermocyst ) After the first hit in day care against the edge of a wood toy furniture,teachers told me he wnated to sleep, as soonas I got there he stand up and in the way home didn t sleep even if Iwas worry after what I was told (I gave him tylenol as soon as Iwas int he car). After couple of days his eyes were little red but went away, i didn t think about until secon hit because he was acting normal.Second hit was Sunday at home against the wall after runing arround my legs ( couldn t catch him), he said hurts but other than that ok. Both cases ice was applied, first bump is still there; I made an appoinment with his neurosurgeon but is until 2/19; should I take him to ER or waiting is ok, if waiting what do I need to watch; thank you