If you track your weight daily and average it out, you might be doing fine. I go to physicsdiet.com (it's free, this isn't a referral or anything-they don't do that) and it spits out charts and things for BMI, body fat (if you use a different calculator or scale to figure it up), calories in and out (if you track your food and excercise-you have to enter it in yourself) etc and plots averages on a chart. Pretty handy for trending.