Weird Discomfort

Ok so I am 4 weeks postop and have been working out this last week and a half (got clearance from dr). I was on the elliptical the other night and I started feeling this weird uncomfortable feeling in my a diaphragm area with each breath. It's sticking around a little and can feel it when I take a deep breath, bend over,and right after eating. Any thoughts on what it could be or what I did. Not too worried, more curious than anything.