Do you recall the specific kinds of changes that you made (e.g. modified widget style, new pages, or something else)? And whether you had manually checked in each change or page?
Another area you can check and compare is your RP backups ("File > Recover File from Backup"). By default, the backup dialog will show all projects that were opened in the past 5 days; you can search back further (max 30 days) by changing the number in the upper-left field.
Hopefully that helps and there's a backup containing the version you have in mind.