3 words - Skin Fold Caliper. It will require going out and buying one OR having someone that has one do the test for you. I prefer the second option as they've already done it before. This little gadget looks like a little plastic Ice Tong. They pinch your tummy, arm and legs. Then calculate your body fat that way. It's relatively accurate and more reliable than online "fill in the blank" calculators.

I think it's easier to track total weight and weigh loss (in lbs and inches) vs how much body fat you have. All you need is a scale and a tape measure for that.

Good luck!