Welcome to the forum - sorry to see you join our 'exclusive club' - the club no-one ever thought they'd have to join xx
Feel free to tell us about your story so far. How long ago was your surgery & what was done?
It is weird, isn't it, @KGEB. I think it is to do with the nerve endings around the lymph nodes ..... there is a weird numbness too, which can take years to 'fix', if ever. There can be a burning pain as well as an ache.
Do you have a breast care nurse? Some gentle massage of the area may help relieve some of the pain - watch out for any swelling & tell your breast care nurse or your surgeon's office if that happens.
take care & all the best with your recovery