I put in tray #4 a day early after 13 days with #3 and it is much tighter. No pain unless I have had the tray out for 30 min to eat. Once I put it back in it feels better. There's a slight discomfort, but only after taking the tray out and the teeth try to move back to their original position. Eating is a 1 out of 10 for pain now.