Yes I have this too and its killing me right now. It feels like my ribs right underneath my chest are breaking or are concave and collapsing in on themselves. I also have back pain in the same area, but only on the right side. It doesn't bother me at night (yet!) but it hurts me all day at work where I sit in a cubicle. It doesn't bother me when I'm walking or standing.
I talked to my chiropractor about it on Friday. She said its probably because I'm carrying high and the baby is putting pressure on my ribs and organs. I did have a few ribs out of place. She did some muscle work in the area, but it didn't seem to do anything. I'm going back tonight. I did put some moist heat on it Friday and that actually did help the aching a bit.
I'm all ears on advice. I'm miserable!!