Scales!!!!
Yep. My doc's scale is always a couple pounds heavier than the one I go by. That is the thing. Go by one scale and don't worry about what any other one says. It is not so much about the number on the scale but how much that number is changing. Personally I like my grandma's scale because it is alway about 3 pounds lighter than the scale I go by :) But I still stick with the one I use here at work because that is the one I have used since the beginning.
Dude I can easily be 8-10lbs more from AM to PM! In the AM I weigh after (emptying my bladder...and "dropin' a deuce") naked. After drinking a gallon or so and eating....plus my clothes it adds up! (water 8lbs...food 1lbs....clothes 3lbs) Just go with your scale......as it will be the one you use as a "tool" to monitor your progress!