Hello, I am Jessie, a 26yr. white Fem. without any chronic medical conditions thus far, whom is having constant severe pain in lft. lung. Started under collarbone 3dys.ago accompanied by swelling. Pain/breathing/mucus has worsened daily. Collarbone to bottom of ribs is region of pain@this pt.(lft. side only).Is this an infection, cancer,S.F., collapsed lobe, or something I am blowing out of perportion????Any ideas or sound familliar?