Repeat, minus the ER visit

He did it again.

He wasn't watching where he was going, ran into the table, and knocked his cheek and forehead.  He fell to the floor crying.  I scooped him up and his eyes were rolling back into his head. His body went limp.  I shook and jostled him until he looked at me.  He was no longer crying.  With a few tears on his cheek he curled up on my shoulder and acted as though he was ready to go to sleep.

Eventually I put him down after I was confident he was going to continue to breathe, and he walked normally, began jabbering, and pulled down a candy cane from the Christmas tree.

I know the ER doctor said some kids do this, but I am having a hard time with it happening twice in less than 24 hours.  I'm worried.  And scared.

His 18 month well visit is tomorrow morning.