Kat, NED stands for No Evidence of Disease
I'm er/pr- so am no expert on hormonals like Aromasin or Arimidex, but ask the onc if,since your're weakly positive, anti-hormone therapy is an option for you?
Some onc's run what's called tumor markers; when I was done with treatment for primary disease, my onc ran those every 6 months when I would see him for my follow-ups. I was scheduled to have follow-ups for a year, then once yearly but I recurred before then.
Any time you have aches and pains that you think are alarming, you should report them, then your onc will determine when to do scans if the aches continue. Some, especially if you're not to far out from ending treatment, take a "wait and see" approach as the residual effects from chemo and rads take some time to resolve. Also, Herceptin can cause some aches. But report what's going on, and I also keep a personal diary where I note symptoms down, that way if something continues for more than two weeks I can point that out, as oncs like to wait at least 2 weeks before ordering scans.
Hope this helps, good luck with your appointment today!
<3 Lolly