I had my TKR in May and you are about where I was at that point. It takes longer than 6 weeks to get a good range of motion and be prepared for good days and bad days. I was at a 128 bend and -3 extension at 11 weeks. The doctor was happy with the progress and said I would continue to gain range of motion. I did aqua therapy as well as land therapy and found that to be very helpful. I think you are doing great! Recovery from a TKR is a full time job and you have to do your exercises on the days you don't have PT. I am still in PT and have just gone from 3 days a week to 2 days.