3 weeks ago I noticed swollen area above left clavicle. Dr sent me for chest xray , full bloods and ultrasound. In meantime I had a course of antibiotics. 

Bloods came back normal. X ray normal just waiting on ultrasound results.

Area still swollen, I have no other symptoms. But my shoulder joint was recently diagnosed as rotor cuff tendonitis  on left side and I get pain down that arm when I raise arm up and backwards.

Could this be causing the swelling , I am so worried it could be serious.

I had double mastectomy in 2012 with no need for chemo or radiation treatment.