it's the infamous three week stall. If you do a search for it on this site, you'll find something like 17,000 posts on it. It happens to almost everyone. And as NovaLuna said, it's not always the third week, but sometime in the first month or so after surgery. Mine was weeks 2 & 3. It broke during week 4, and I lost like 6-8 lbs within a couple of days. Just stick to your program and stay off the scale if you need to - and rest assured that it WILL break.