1. This is the full tracking of your parcel:

China Post Register Air Mail Tracking System
Parcel No.RM712206519CN tracking result
2016-07-20 17:02:51.0 南阳city 大宗parcel 集中shipping center received
2016-07-20 19:25:08.0 南阳city 大宗parcel 集中shipping center customs scan
2016-07-20 19:49:32.0 leaving 南阳city 大宗parcel 集中shipping center ，next station 南阳center
2016-07-21 13:57:29.0 郑州Transit Station export security scan
2016-07-21 14:25:07.0 China Post Group 郑州international parcel 指定Transit Station export customs cleared
2016-07-24 14:49:00.0 郑州international departure

2. I also found this:

International Mail# RM712206519CN Tracking Result
Summary
Tracking number Origin Destination Status
RM712206519CN CHINA UNITED STATES On route

History Detail
Local date/time Activity Location Remarks
20-Jul-2016 17:02 Received by Post Office 47300221
21-Jul-2016 14:25 Departure export customs ZHENGZHOU

3. The last tracking of your parcel is this:
2016-07-24 14:49 Zhengzhou international shipment

4. Your parcel has departed China for USA and is On Route there. Unfortunately USPS does not track Registered Mail from China Post so you are left in the dark about the whereabouts of your parcel. I don't see any problem with your parcel. Eventually it will show up at your address.

5. China Post Airmail Parcel Estimate Arrival Time for USA can be found here:
http://track-chinapost.com/China_Post_Arrival_Time_Stat.php

Hope this help.