Relax. Your weight will fluctuate a few pounds here and there. You'll have days where you won't lose any. You'll have plateaus. It's normal.
Example: I weigh about 5lbs more with PMS than I do without. I weigh more in the afternoon than I do when I get up.
Ditch the scale - it's not your friend. Measure instead (but not every day!). You'll drive yourself crazy.