Slimming belt does not cause any spotting. The reason for the spotting could be your PCOD
. Though, you should try other means of reducing weight like eating a low-calorie, low-fat diet rich in fresh fruits and vegetables, having a regular fitness workout or just a 30-minute brisk walk everyday. Drink plenty of water. Another reason for the mid-cycle spotting is the ovulation bleeding. Please consult your gynecologist for further suggestions. Take care.