Stacking % off coupons at CVS

Has anyone had any luck stacking multiple percentages off a single item + full purchase coupons? I was able to apply the discount (along with my ECB and MFR coupon) to my cart online set for in-store pickup, but I'm afraid that the deal is so good that someone will cancel the order, and I end up losing my coupons. Nothing in the coupon details specifies anything about stacking these types of deals. For context, this would bring a $140 item down to less than $40.