1. This is the full tracking of your parcel on the China Post EMS site:

2016-12-25 00: 00: 00.0 19:08:42 Shanghai arrival processing center, from the bulk delivery office

2016-12-25 00: 00: 00.0 20:19:00 Courier bulk receiving office to receive

2016-12-25 00: 00: 00.0 21:03:00 Courier Delivery Departure Processing Center for Shanghai Post Express Logistics

2016-12-25 00: 00: 00.0 21:05:05 Courier delivery place to leave the processing center, sent to Shanghai

2016-12-25 00: 00: 00.0 23:01:29 Shanghai to leave the processing center, sent to USJFKA = ISC NEW YORK NY (USPS)

2. Somebody should have told you this:
The number starts with “E” and ends with “CN”, i.e. EE123456789CN, EA987654321CN
This is China Post Express Post Service (EMS). Normally it is much faster than airmail and might take one to four weeks to arrive. The price is also much higher than airmail.

3. Now that said, in very good condition EMS parcel to USA can be deliver in less then 14 days. Unfortunately in Shanghai and JFK there having problem with to much mail.

4. In Shanghai parcel a reschedule due to lest room on flight for mail bag and smog have affected the departure of flights. In JFK, 2 European countries have told their client that JFK was overwhelm with incoming parcels from Overseas so the parcels will be late.

5. Just continue to track your parcel on the USPS site for any new movement. You could if you want to advise your seller that you have not receive your parcel. He might be able to Call China Post EMS; 11183 and get more information about your parcel.

Thanks.