A cough is normal. You have to have hold a pillow on your chest to prevent damage when you cough.
Since ribs are cut during surgery there would be some grinding. Take it easy, Don't lift anything over 5 pounds.
I'm surprised you were not informed of this after surgery. When I had OHS, a pillow was provided to take home. It shaped like a teddy bear pillow shaped like a heart, not one to sleep on. There is another name for it
I was in hospital for 23 days.