I've been a little frustrated with the scale not showing a consistent drop in pounds, but apparently it's not just the food you eat or the exercise, it's your body adjusting which depends on: The amount of salt you eat, if you eat a lot of vegetables with a high concentrate of water, how your body is processing food (waste), etc. Also take into account the time of the month and any medication.
Sneaky Weight Gain Offenders
To combat feeling frustrated with the scale, make sure you measure yourself each week, that will show if you are on the right track and often shows losses when the scale doesn't.