Rep range to burn fat

I'm doing a workout in one of the Muscle and Fitness magazines that consists of varying rep range for the different muscle groups.  Here is an example for chest:

bench press 3 sets 4-6 reps

incline dumbbell press 3 sets 6-8 reps

incline dumbbell fly 3 sets 10-12 reps

cable cross overs 3 sets 15-20 reps

Doing this type of workout seems to make me heavier and I weigh more on the scale than when I strictly do high reps between 15-20 rep range.  I want to lose 20-30 pounds and don't know if the heavy weight and low reps is causing my weight to increase.