I Am 69, Normally Active. I Had A Tkr On

I am 69, normally active. I had a tkr on May 16, and by mid July was walking an hour and a quarter, very pleased. Then I did a little too much (about an hour up and down trail, and about 20 minutes of stationary biking). After that the connective tissue inside my operative knee started to hurt even when I walked a block. This has continued for the last week and a half. What is going on? So I have been doing very little exercise (a bit of stationary biking and not much walking at all.) I ice it and take advil. How long does it typically take to get out of this type of downturn?