Hello! I am a 47 year old and after scrubbing the interior of a two story, 3000 sq. ft. house including walls,base boards, trim, and so forth two days ago I. Am in pain. Why am I having really sharp, stabbing, pains in my upper right pectoral muscle that is so sharp that I can't breathe in deep or out too hard or the sharpness of the pain takes my breath away and scares me.