Mine was one doctor too. After my knee op, I saw the surgeon for the follow up, and he was surprised at how much pain, swelling and stiffness I still had. He hoped it would improve. I saw him again 6 weeks later, and by then had the colour and temp changes going on. I vividly remember him putting his hand on my knee, frowning, putting his other hand on my good knee, and frowning as he compared the two. Luckily that day my knee chose to give a small demonstration of the colour thang

and he saw it clearly. He as ked me some pertinent questions and said 'I think you have something called CRPS' and explained it a bit. He referred me to a pain specialist that day and wrote to my GP.
Goodness knows what happened in the op, but I can't complain about his diagnosis and prompt action.
Mine was 2 months from op to CRPS diagnosis. One hydrotherapy physio, and one surgeon who diagnosed it.
Bram.