Welcome in H.C.M.
I have gone through your query regarding ear pain
of your child after sustaining injury
by hit on left cheek.
Here I would like to tell you most probably your child had got hit on his lower jaw and this is made of mandible ( bone of lower jaw ), Head of mandible makes the anterior wall of ear canal
. It is usual that hit on one side always pushed temporomandibular joint of opposite side posteriorly and leads to bleeding from ear .
This is a minor injury and self limiting, usually ear drum and inside of brain remain safe. Your child had no symptoms of intracranial injury so no need for worry.