Retrieving Lost Data

As I work on a new page, I "save as" and then "save" periodically. At times, if I hit the Backspace button a few times to make changes, it will erase all of the data on the page. Seems the page saves automatically without asking at that point and I can't retrieve my work. Don't know if I can indeed retrieve it or if I have a computer/keyboard issue or if this is a program issue. I've only had this problem this year.