That could be a number of things. Water retention, you decreased your meals, snacking too much, your menses. Give yourself some time and stay consistent. I know is hard to stay consistent at first, but you'll get there..
Water retention I really don't know.... have been same weight for months now, not a pound less or mode varies , my meals actually increased to 5 a day (versus 2 a day I used to make), snacking I've drecreased around 70-50% and my new snacks instead of brownies and bread are Special K bars, 100 calorie diet bars, banana or watermellon.... so I am a little disapointed with the fact that I started eating better both in quantity and quality, started excersizing pretty strong and am exactly were it started at.... must admit it saddens me but I will of course continue in the same track, I want this to be my life style not just a way to be thin....