if you have a shake before bed, make sure it is low carb (water and protein, if possible).
i don't know what your daily caloric intake should be, but make sure you maintain that.
what kind of exercise are you doing? remember that if you are doing weight training or any heaving running, biking, etc, that you will be gaining muscle and that will sway the scale. The best measurements are done with tape and not with the scale.
it is recommended that you do at least 20 minutes of solid cardio every day to lose weight. I have been working out for almost 5 weeks now, 1 hour every day at a cardio-bootcamp, and i haven't lost a pound, but i can see that my arms are bigger, my chest is tightened up, and i have more definition in my stomach.
this may sound annoying, but there is no quick fix. it can take time depending on your metabolism and how long you have been at your current weight. Never think that the work you are doing is useless if you aren't losing weight because you will find that you can go longer and breath easier the longer you do that ... which means that your internal organs are getting healthier and that is just as important (if not more) than your overall body shape. It'll come, you just have to be patient. Exercise should be a life goal, not a month-to-month goal.