Have you weighed yourself on the same scales, same time of day, wearing the same clothes as before? Are you exercising a lot?
Don't despair you'll be amazed on this diet how the lbs can drop off you literally from one day to the next. Also TOTM can make a difference for some. Hang in there, keep 100% and wait and see how you've done on your weigh day, you maybe pleasantly surprised. As long as you stay 100% the weight will come off.
I definitely felt flat and a bit down for a few weeks after my first week. I think its after the euphoria of the fantastic first weeks loss comes the realisation of how many weeks and in my case months you are going to have to stick to this bland, boring diet to lose all the weight you need to lose. But if you can just keep going once the losses build up and you can see and feel the difference it gives you the resolve to keep at it.
Hang in there!