1. This is the full tracking of your parcel:
China Post Register Air Mail Tracking System
Parcel No.RH341404303CN tracking result
2016-08-26 19:08:03.0 Guangzhou Int'l Parcel Center received
2016-08-26 19:08:12.0 Guangzhou Int'l Parcel Center customs scan
2016-08-26 22:13:21.0 leaving Guangzhou Int'l Parcel Center ，next station 广商大宗
2016-08-28 01:25:31.0 Shanghai Transit Station export security scan
2016-08-28 03:43:21.0 Shanghai Transit Station export customs cleared
2016-08-29 23:56:00.0 arrive Shanghai Int'l Airport
2016-08-30 00:03:14.0 leaving Shanghai Int'l Airport going to next airport/seaport
2016-09-01 17:38:00.0 Shanghai departure

2. I also found this for you:
International Mail# RH341404303CN Tracking Result
Summary
Tracking number Origin Destination Status
RH341404303CN CHINA UNITED STATES On route

History Detail
Local date/time Activity Location Remarks
26-Aug-2016 19:08 Received by Post Office 20023712
28-Aug-2016 04:02 Departure export customs SHANGHAI

3. So we no now that your parcel has departed China for USA. Unfortunately you will not have anymore tracking for this parcel because USPS does not track China Post Register Air Mail.

4. May I suggest you read this for USA:
http://track-chinapost.com/China_Post_Arrival_Time_Stat.php

5. To me your parcel is fine, when it arrive in USA it will go through the US Customs Office, then the parcel will be given to USPS for delivery.

Hope this help.