Hi Stripey
I had this with both boys and have a little this time, but nowhere near as bad.
With the boys it was mainly my feet, hands, knees and hips. Bizarrely the middle joint of the forefinger on my right hand was the absolute worst. It used to get red hot and swell up.
I was also much worse first thing in the morning, I used to have to wait in bed for half and hour slowly and gently moving my joints, then go downstairs on my bottom.
My GP assured me it was hormonal/related to and excess of relaxin and would improve when I stopped breastfeeding and it did, both times.
Its nowhere near as bad with dd, but I do still have some pain in all the same old places this time.
I was on another thread about it recently, which annoyingly I can't seem to find now, it appears to be more common that I realised as lots of other ladies had the same experience.
It could have been your sedimentary rate or ESR that was raised. This is an indicator of inflammation in the body, but unfortunately doesn't point to whatever is causing the inflammation. My ESR has been raised at every blood test I have had while I have been breastfeeding dd (and there have been quite a few blood tests, what with one thing and another).
Given that you have now stopped bf, I would perhaps do what you suggest and give it another week or so then go back to the GP.