Dex is right.
also if your water intake is too low, or your sodium intake too high, you'll be retaining water.
Crash diets are very bad.
I lost over 42lbs inside a year, when I got a cross trainer. I spent 2hours on it a day, every single day. I didnt even work up much of a sweat, I just did light exersise instead of sitting on the sofa. I didnt change my diet at all.
Its not the best way to loose weight, but at the time I didnt know anything about fitness and diet. But at the end of the day, If your moving, your burning cals. There are good ways to loose weight and better ways to loose weight, but keep it up. Dont stop moving, even if its slow walking or tai chi.
The good thing about weight training is that your burning cals even when your asleep. And your never hungry, cos as long as your eating the right food, you can eat as much as you can stuff in your face. Its great!!!!