armpit and shoulder pain, burning under collar bone

I have recently (about 1 or 2 weeks ago) had armpit pain that lasted a full day, and intermittent pain since....  prior and still continuing I've had an intermittent burning under the collarbone...  I have had a discectomy about 3-4 yrs ago at C4-5 I think.  I am not very active due to Lupus, RA, Osteo, Fibro, Raynauds,Sjogrens, acid reflux and a hiatal hernia.  I have also had intermittent pains directly behind my left nipple for years.  I was told that was from stomach issues.  I have seen my heart doc, internal med doc and ortho surgeon and have a stress test scheduled for next week.  Any other areas I may need to look into?  So far I DO know that I have another bulging disc below the discectomy but doc doesn't think that is the cause.  Heart doc has concerns about pain beneath nipple and is taking action.