I am a 9 year breast cancer survivor. I had a flu shot last week and woke up the next morning with a small hard lump above my clavicle bone on that side. I believe the knot is new. I took the flu shot in my arm where my lymph nodes had been removed without thinking. I went to my physician and she ordered an ultra sound . The ultra sound showed I had a perfectly round knot with no blood supply about the size of the pea. Their diagnosis was non cancerous. The area where the lump now is puffy and I can t feel the lump as easily. The doctor or the radiologist did not think a bioposy was necessary. Your thoughts?