Pro allows you to access only 1 previous reconciliation report (Premier allows access to all). A possible workaround is to make a backup first, then undo each reconciliation (opening and saving each previous reconciliation as you go) until you get to the one after the one you need, then open that previous reconciliation and save it.
Going forward, you should always save your reports as PDFs.
Allow me to join the thread and help share additional information about printing previous bank reconciliations in QuickBooks Desktop (QBDT).
QuickBooks Desktop Pro only allows you to access the last reconciliation report created. However, QuickBooks Desktop Premier, Accountant and Enterprise give you access to the last 120 previous reconciliation reports.
To view the previous reconciliation report:
Go to Reports at the top menu bar.
Select Banking.
Click on Previous Reconciliation.
In the Select Previous Reconciliation Report window, choose the appropriate Account and the Statement Ending Date.
Choose the Type of Report.
Choose the type of transactions to include in the report.
Another work around is to take a back up of the file to a friend who has premier (same year or higher), premier can open the past recons in pro, then print them to pdf and take them with you on a usb stick. Then as Memere says, in the future print to pdf when you finish the recon