It's possibile in report of contributes, check for single contact a total amount of contributes pending? Or have a difference between complete contributes and pending contributes? thank'you
Have you tried Reports > Contribution Reports > Contribution Summary Report? You can add a column to show the contribution status and you can modify the filter to show whatever status you would like on the report. By setting the grouping options to Contact and Contribution Status and nothing else, you will get a single row totaling contributions by status, and then a total row for the contact, but this will not give you a difference between the two.
Hope this helps! Tamar