What does "missent" status of the USPS packaging in tracking mean?

[Jodiawswawn]

I didn't get my USPS package. When I try to track it via the USPS site, I get the "missent" status.
YOUR LABEL NUMBER
SERVICE
STATUS OF YOUR ITEM
DATE & TIME
LOCATION
FEATURES

927489999830655XXXXXXXXXXX
Package Services
Missent
August 17, 2012, 10:30 am
Expected Delivery By:
August 16, 2012
USPS Tracking / Delivery Confirmation™
Arrival at Post Office
August 15, 2012, 3:28 am
OREGON CITY, OR 97045
Electronic Shipping Info Received
August 13, 2013
Shipment Accepted
August 12, 2013, 5:02 pm
PORTLAND, OR 97208

What does the "missent" status in USPS tracking mean? What do I have to do to get my package?