I have a slightly different situation myself. Got shipping notice on 12/4, it started tracking, but then abruptly stopped on 12/9 at a post office about 30 miles away from me. No tracking since then. I'm wondering if this is possibly lost in the mail, or sitting in a warehouse with all the other Christmas packages waiting to be delivered.
Last year, I had a package not show up for over a month. I filed a lost item report with USPS and it still didn't resolve anything. Then one day, it magically showed up after I had given up on it.
Don't worry about your item yet. It will most likely show up as its probably delayed during this busy time of the year.