Hi, I am a 24 year old female and I have recently started having upper back pain on the left hand side, when I touch it it feels slightly swollen compared to the right side of my back. The pain is mild but I can feel it more when moving around. I also have left leg pain and and pain under and my left breast (that has been going on since last year, have been to the doctor a number of times and had an X-ray , they dont know what is causing the pain, X-ray cam back clear). Do you have any idea what this could be and why my back is suddenly hurting?