Check weight level. Check your weight on a scale everyday. Also, write down what types of food you consume and count your calorie intake for each meal.
Weighing self. I agree with dr. Gupta and would say that you should only weigh yourself on a weekly basis-- same day, same time, same clothes. The main byproduct of the breakdown of fat is water, so when you lose weight, water is released back into the system and that fluid retention can influence the scale, especially for women premenstrually.
Monitoring Calories. Self-monitoring in weight management means monitoring your behavior to avoid eating high calorie food and trying to include some amount of physical activity daily in your routine. Some people recommend weighing yourself daily and some says weekly. If you gets upset and lose motivation after seeing a small weight gain then weight weekly but ideally that small weight gain can be a motivation as well.