I noticed a few days ago that when I inhaled deeply I could see a bump located on my chest where my solarplex is located. It's an uneven bump and not exactly in the center of my chest either. As of late I've been suffering from heartburn quite often, and it's as almost as if i can sense it originating from this mystery bump. When I touch it I feel slight pressure, and If i continue to irratate it It begins to become borderline painfull.

Would anyone happen to know what this could be?