Please excuse my tardy response. Welcome to the Pain Mangement Forum. We are really more geared towards chronic pain, There are no physicians on this forum.
There are multiple conditions that could account for your pain, including fibrocystic breast tissue. Or the cartilage of your ribs could be inflamed in that area. these are only guesses and possibilities.
I encourage you to consult with your PCP.
Please know that you are always welcome here but you may find more suggestions on a different forum. Maybe the Family Medicine Forum could provide better suggestions or select from one of the physician headed forums. Just click on the top of this page on the word forums.
Please let us know how you are doing...and again I suggest that you consult with your physician.