I don't know, there's usually small fluctuations in your body weight based on solid/liquids in and out. I wouldn't beat myself up over 2 lbs if I were you, just stick to your diet. Maybe split the difference and weigh every few days or so.
About scales, I have a Taylor digital. I don't have a whole lot of faith in it. The battery is a lithium one and when it goes I may have to just get another scale.