I remember after my lumpectomy I had quite a bit of pain under my armpit where the lymph nodes were taken, apparently it's seroma (flood retention). Since having my bilateral mastectomy with immediate reconstruction. I can say that my breast and tummy area pain has settled down but my armpit is still sore. I am massaging the area twice a day and my surgeon says it will take a while for the seroma to completely dissipate. All I can do is be patient. But Deanne is right, see you breast surgeon again to get your pain checked out. They'll be able to get to the bottom of it.
Welcome to this site Annie, not that any of us want to be here. I hope you find posting here as satisfying and reassuring as I have since starting back in. May. The wonderful love and understanding from our Pink Sisters is amazing,
Good luck with your radiotherapy and I hope Deanne is right again and it will be a breeze for you.
Love and hugs
Janey xxx