CVS couponing question

I see so many people post their hauls from cvs with coupons and I’m always floored at how cheap it comes out! Last week was my first week trying couponing at cvs and I think I did pretty well. Im looking at hauls for this week and I’m confused. So many times the person will list the coupons they used for the purchase and say that the coupons can be found in the cvs app. But half the coupons aren’t in my app? Is it possible that I used all these coupons last week? But isn’t it new coupons every week? Why would I have different coupons than everyone else?

If anyone can explain this to me I would really appreciate it. Im new to this and still getting the hang of things.