Coupons not working at walgreens??

I was doing the loreal and maybelline coupons with the clearance makeup and got my total down to $1.45 or something for the total with the coupons coming off. However, when I go to checkout it shows the total as full price (like $20 something). Does this happen to anyone else? It's so irritating. I thought maybe it was because my cart wasn't $10 so I added more stuff and it still happens when I go to checkout.