I agree with some of the others-we need to know exactly what you are doing, diet and exercise-wise. I can "try" to count my calories, make healthy choices, and work out-but trying and doing aren't always the same thing.
Also, it is very common sometimes for me at least, to some months lose pounds on the scale, and other months lose inches. (I measure myself once a month.) Some months I might lose 4-6 pounds, and others nothing-but I might lose an inch in my waist that month-so its ALL good.
What kind of plan, dietwise, are you doing? How much exercise are you doing? I must also stress the importance of working out-it is the only thing that gets you FIT and FIRM. You can diet, diet, diet and lose however much you want to...but you won't ever get the firm thighs or abs that you might want without working out. There are lots of "skinny fat" people out there. (Thin people who still have flat butts, soft bellies, or jiggly arms/thighs.) They might be a size 4 or 6...but still don't look their best in shorts or swimwear. It takes both for good health, and a good body.

Cutting calories even more than normal to make up for not working out isn't the best thing to be doing...