I have been referred on 2ww to breast clinic for a fairly large lump my doctor found in my right breast (I do regular checks but would have never recognised what doctor found as a lump.) naturally I am worried sick. I had my 2nd jab Pfizer yesterday and my appointment is next Wednesday. I've just read that the 2nd shot can cause lymph node swelling in arm shot was done. I expect an ultrasound or mammogram of right breast and I am worried any swelling in this armpit may confuse the diagnostic tests. Anyone else know anything about this?