If you are in a house, keep in mind we use the US Postal Service and boxes are left in your regular mail and not normally at the front door. Be sure to check with others in the household to help locate the box. All shipments must be physically scanned in order to show delivered.
If you are in an apartment complex, we use the US Postal Service and boxes are not left at your door but should either be in your locked mailbox or (just as likely) left with the front office of your complex. Since boxes must be physically scanned in order to show delivered be sure to tell them you have confirmed delivery so they attempt to locate the box.
On extremely rare occasions the Postal Carrier will "pre-scan" all of their boxes for the day which makes them appear delivered but they don't actually get delivered until the next day or so. This is more common around holidays but we do see it happen. Please be patient for another day or so and the item should show up!