This may happen for several reasons.
1. USPS sometimes shows tracking as delivered but may show up the next day or so.
2. It has been left in front of your door and someone else took it. If you are not available to take in the package in person, we advise you to leave a note for the carrier not to leave the package outside the door or to have it delivered to your neighbor who can receive for you.
Either way, please contact your local USPS or UPS right away. As an online store, if the tracking shows delivered to the right address and zip code, we are not held responsible for lost or stolen packages.