The exact same thing happened to me. 20 pounds in ten days then 2 1/2 weeks and not one pound lost. It just seem physiologically how could this be. 3500 calories is a pound. If we eat 1500 calories less a day and exercise we should easily drop 3-5 pounds a week. Not me! Went almost 3 weeks without a loss, but at least now at five weeks I started losing again.