I have that too. If it's anything like I have, you've pulled an intercostal muscle.
It's right in that area you're describing.
It takes a while to go away, since it's not an area where you can restrict movement.
I find that even when I take a deep breath I can feel it. Not pleasant, but nothing to worry about if it is an injury of this sort. If you place cabinets for a living this makes PERFECT sense! Feel better soon.
Sue
