If you're a female, are you coming up on that time of the month? My situation sounds very similar to yours. I did preconditioning for 4 days, then went from the yellow to blue to green diet in the presribed time and did great. (Lost about 10 lbs) == Now I"m stuck. I haven't lost more than a pound this week --and I think it's because of the whole TOM thing. In my case, I went on vacation during this time,too. I didn't follow the plan exactly as far a scheduling meals etc, but I didn't eat foods that were off plan and my body never went out of ketosis -- I checked once a day.
So... I'm hoping for both our sakes it's period related....unless you're a guy in which case, i'm hoping something altogether different for you!