A vaginal discharge helps to keep your vagina moist and comfortable. midway between periods; when you have an IUD; during pregnancy; after sexual. Progesterone IUDs tend to make cervical mucous lighter. Anything which makes the vaginal walls inflamed will make vaginal discharge heavier: infections such as thrush candida or bacterial vaginosis for example. Remember that the more sweat there is in vaginal discharge, the more likely it is to smell.