Among all your body parts, your belly is most likely to be influenced by weight affecting factors such as dehydration, bloating etc. However, these changes being transient cannot be taken as parameters of your actual weight. You shall set an objective to measure your waist and butt size once or twice in a week to know your accurate measurements.
Consider Rest
To drop unwanted weight and to sculpt your body, you might feel enthused to practice crunches and varied other workouts for all the seven days. However, by doing so, you only snatch recovery time from your body because workouts cause muscle tear in your body. And when you continue practicing exercises without rendering any rest to your body, you only make the recovery process difficult for you. Ideally, five days of exercises in a week are sufficient enough to provide full workout to your body. However, if you feel slothful in the dearth of workouts, you can opt to have brisk walking, hiking, biking, swimming etc. on rest days.