What Causes Pain Around Xiphoid Process?

I am a 39 year old male, 5'9'', 179 lbs and I excercise frequently. Recently I have had a pain around my xiphoid process. I am unsure if I injured it while wrestling with friends in a pool or if it is something else. I didn't notice until my youngest son put his elbow in my chest by accident when I was lying on the floor and I felt alot of pressure and a very uncomfortable feeling in that area. It felt like I had a burning sensatiion in my chest that lasted for about a day and a half. Also, when I push around my xiphoid process it feels bubbly, as if there is fluid or something. When I bend forward it feels as if there is some type of pressure in there. I went to my family physician, he listened to my chest, lungs, pressed here and there and feels that I just injured that area and to give it a couple weeks. Is it possible these are symptoms to something more than an injured xiphoid process?