My 14 Month Son Fell And Hit A Metal Corner.

My 14 month son fell and hit a metal corner. I saw a dent like the size of a dime appear. After a while it filled with a swollen bruise and I thought it went away. My son acted normal. He cried a little when it happened but started playing shortly after. Not until bedtime (3 hrs later) did I realize, the bruise was actually soft. It's as if the dent is still there but the swelling makes it look normal. You can see the dent right now, you could just feel it. What can I do? Will the dent go away? I left his doctor a message already and I'm hoping to get a response soon.