Hi Irina - when I had my mastectomy & nodes removed in 05 I had pain in my arm and was unable to reach for the sky.  The surgeon later told me he may have caused some nerve damage.  I eventually got over it by using some of those stretchy yoga bands, or using the wall and slowly walking your hand all the way up till your arm is in the raised position.  And now that I am in radiation (cause my cancer returned) my radiation oncologist tells me to do this rotating motion, with my arm bent and hand on my shoulder. Since you did have nodes removed, please be on the lookout for possible lymphedema.  It doesn't happen all the time, but if you feel like you have a wing or that your arm is heavy it could be fluid backing up.  if that happens ask your doctor about seeing a PT that specializes in lymphedema and about getting fitted for a compression sleeve, because having lymphedema can be a serious complication of node removal.  but the more you know about it the better you can be prepared for it. best of luck to you! Angi