I was playing basketball today and another player threw their shoulder into my chest really hard. It caused slight pain at first, but its gotten progressively worse throughout the day, and it feels as if some part of my sternum must be broken. It causes considerable pain to do the following: Inhale deeply, Lay flat on my back, Lay on my chest, or apply pressure to the center of my chest. Give it to me short doc, how long do I have?