I weigh myself once every week, first thing in the morning after using the loo, before eating breakfast, in the same spot in the kitchen, no clothes. It's the only way to get a reasonably accurate, consistent reading on home scales. EVERY SINGLE SCALES are different, and her's might not be as accurate as yours or may be more, who knows? The point is, you'll ALWAYS get a different reading on different scales, and remember, weight fluctuates tons during the day, let alone the week. I used to weigh myself everyday, but that was stupid, really does your head in how much the damn thing fluctuates. You might drink more one day and not realize you did so (weigh more) or it could be a hotter day than normal or you exercised more and so sweat more (lose weight.) Best thing to do is just write down the weight each week, then at end of the month calculate how much you've lost - if it's no more than 2lbs, you're not really losing enough. 1lb/week is safe, generally (unless you're really overweight) - and vice versa, they tell me to gain 1lb/week, as it's safest amount in that amount of time.