Hi there i really wouldnt worry about this i had a right bad left boob couldnt move my arm either yet loads movement in the right 1..
have you any swelling on that bad 1??
i did have on mine tuened out to be a hematoma which is nothing to worry about it goes on its own but my left was really limited..
im 5wks now and believe it or not ive just yesterday got over the last of this pain on that side…the arm thing came bk after 2 weeks then i was sore and swollen the surgeon recommemed to me limiting that arm as much as poss and if swelling get coll packs take the painkillers etc…
rest good food and plenty of water xx