I've said it once, and I'll say it again: the scale lies. Bathroom scales are notorious for inaccurately representing body composition. Focusing on those tiny numbers daily is a recipe for not making progress in your fitness and fat loss goals.
What you SHOULD focus on is fat loss. It's not unusual for person to actually gain weight as they get in better physical condition. This is because you are gaining lean tissue (muscle), which is metabolically-active -- unlike body fat. In other words, fat burns zero calories at rest while a pound of muscle burns around 50 calories per day doing nothing more than sitting there.
The good news is that even though people see their scale weight go up after starting to workout -- they usually come down as they add lean tissue. Sometimes it takes a month or so, but you should really be focused on how you look and feel, instead of what a machine tells you.
Confused? Check out this article that explains why calculating your body fat is more important than scale weight.
Best of luck!
matt