Which report will show you a list of members with a pending cancel?
The Membership Cancel report, found in Reports/Memberships will allow you to see a list of memberships with a pending cancel. This means that they have an effective cancellation date in the future. When running the report, choose the query drop down and set it to "pending only". You can see the entered date and effective date on this report
On the view memberships screen you also have the ability to find pending cancels?
View memberships/Query Memberships - Active/Custom Query/ click Has Pending Cancel: