Documenting and saving your search will save you time. There are two ways to save your work.
It's a best practice to document
Keep this in your existing search document, which can be either a text or spreadsheet format.
In the interest of evidence-based medicine and open science, you should know how you arrived at the results that you did. To that end, your search should be reproducible and transparent, so that anyone replicating your search could arrive at the same set of results.
Increasingly, journal editors are requesting the search strategy to be submitted as an appendix along with the manuscript. This will help you describe your search methodology in your publications and provide the steps which you used.
Saving your search will also save you time later. At any point that you choose to revisit or revise your search, you'll be able to see what you've already done.