Keynote

I converted a PowerPoint to Keynote. I completed editing a 37 page Keynote document. I needed to check original version and when I went to back to original PP and opened it as a Keynote document. When I went to close the new Keynote document it ask me whether I wanted to replace old version. I wasn't thinking and said yes. Now my fully edited 37 page Keynote is back to the original. Is their anyway to get the edited version back?