That would be extremely unlikely but even if you did, websites can be restored from back-up.
You can schedule website backups on a regular basis, have them made for you manually from time to time, or you can set up a backup service that makes a backup whenever you make any changes to the website. As long as you have some backup available that is not too far behind the current version of your website, you need not worry.
You can even restore a page to an earlier version if you just messed up one page.
