Sorry to hear about your diagnosis--how scary! You're in a good place though, as far as the treatment and expertise that is available to you. As far as the potential for lymphedema, that is not an area I know much about (despite being a nurse) but it sounds like you've already gotten some good info. Like others, I think that if anything the exercise would be helpful because lymph is pushed along by muscular contraction. I'm wondering too if swimming might be a beneficial exercise to add to your routine--seems to me like the pressure of the water might help move things along too. Maybe somebody can give further info on this?