The tracking system is only as good as the employees that scan the bar code on the package at each step. I have had packages that are scanned when I drop them off at the PO and the next update I get is that it was delivered. No interim updates along the way.

If you don't see any movement on the package soon, contact USPS by phone: 1-800-ASK-USPS® (1-800-275-8777). (I know - you will wait on hold.) I have done this before, and the operator says they cannot tell anything more than the internet tells you, but every time I have done this, the "problem" seems to get resolved. Good luck.