@Angel61 I have had a recurrence but at the 4yr mark, and it was painless growing in my scar tissue from the lumpectomy 4yrs before. It's not unusual to have pain to be honest post surgery for some time and also radiation. It sounds like it's due to those things as nerve endings particularly in the armpit hurt for a long time after. You could always check with your Breast Surgeon or Oncologist or even Breast Care Nurse if you have concerns.
I recall after radiation in 2011 after about a year or so I too had chest pain which turned into back pain, really weird, turns out it caused constant cramping in my upper body and still til this day. I couldnt have rads in 2015 at recurrence as you can only have it once. But radiation created alot of pain post for me and unfortunately chemo adds to it as it shrinks the sheath over the muscles so causes constant cramping throughout my body. Magnesium is excellent for it which I take daily for 2yrs but as my GP said, the damage is too extensive for relief.
Definitely contact your professionals for peace of mind. Hugs Melinda xo