I had my right knee replaced on 1-23-2019 and yes, it can get worse before it gets better. Initially, my in home PT told me to do my exercises 3/day even though I had an immense amount of swelling. When I went to outpatient PT they told me NO, NO, NO. Now I do them 2/day it's much better. Whenever I try to do more, I pay for it with pain and soreness. To answer your question, yes. You can do too much, too soon other than with stretches. You can do those as often as you like. Always follow the advice of your doctor and PT because every person is different. If I didn't have excessive swelling, I would be doing my PT 3/day but after trial and error, I'm finding a middle ground. You will too. When you do too much, take note. Every week, they give me more exercises to do so I'm not staying stagnant. There are definitely good and bad days for months following this surgery. Slow and steady wins the race.