I would not back down telling your doctor if your pain doesn’t get better, especially if you feel you tore something. 6 months out I tore my one hamstring tendon and didn’t even know it. I had pain for months on the outside, lower portion of my knee whenever I walked and my doctor said it was probably tendinitis and we’ll see how it goes. Then one day I noticed this concave area and bruising, red blotches in that area. I waited a month to say something and when I showed my PT, he sent me to my orthopedist. My orthopedist said it was only the second time he’d seen it in 20 years of practice! Lucky me -lol. He said there was nothing to do about it because we have three other hamstrings and the tendon is probably curled up behind my knee. My point is, I feel like I wasn’t assertive enough when I was having the pain when walking. Not sure what he would have done, but I wonder.
That said, TKR recovery is a long process and I am 4 months out from my second knee. Recovery is a marathon not a sprint. Keep moving!