Diapers on my registry

My shower is this weekend and I've been checking my registry (even though I know I shouldn't). I'm very happy and grateful that a lot of the items have been bought. I am curious though, no diapers have been bought. I put only pampers diapers and wipes on the registry. I've read into diapers a lot and that's what hubby and I decided on going with. So my questions are...
1- Do you think I'm not gonna get any diapers since none were purchased from the registry?
2- Do you think people will just buy whatever brand they think is good?
3- Can you return diapers (unopened)?
4- If you can return them, how do I know where they were purchased from?