When using the progressive scanning feature you are unable to tell from the scan list if your web application has been completely scanned. In the GUI the progressive scan count will increase every time a scheduled scan is completed.
To find out if your scan has finished scanning the entire site then you can use the information from QID150024 and QID150021 in the scan report. If the progressive scan didn't complete, you should see the following under QID 150024 in the scan report:
If the progressive scan finished completely, you will not see QID 150024 in the scan report.
Also look at Scan Diagnostics (QID 150021) because it will differ from one scan to the next. As it will show you the tests that have been completed in a previous scan.