1. As far as I can see from the below tracking, your parcel departed China on the 24 July for USA:
http://www.track-chinapost.com/track.php?code=RM712206519CN

2. May I suggest you read this for your country USA:
China Post Airmail Parcel Estimate Arrival Time
On this site:
http://track-chinapost.com/China_Post_Arrival_Time_Stat.php

3. Also please be advise that the parcel can not be track in USA.

Hope this help.

Quote from olives on July 30, 2016, 19:19
My traacking number is : cp314917691cn. Hs result says your item was collected(GuangDoneshezhenshi tY) at 2016/07/16). Where is it now and when will it arrive nigeria.

1. This is the full tracking of your parcel:
Parcel No.CP314917691CN tracking result
2016-07-27 10:56:05.0 Shenzhen Transit Station export security scan
2016-07-27 11:00:28.0 Shenzhen Transit Station export customs scan (domestic transit )

2. Your parcel has been in the china Post system only since the 27 July. May I suggest you read this for your country Nigeria:
http://track-chinapost.com/China_Post_Arrival_Time_Stat.php

Hope this help.

Quote from olives on July 31, 2016, 15:12
Please, dear concern. Is my parcel still in china. Cp314917691cn.

1. This is the full tracking of your parcel, it was mail only on the 27 July.

China Post Register Air Mail Tracking System
Parcel No.CP314917691CN tracking result
2016-07-27 10:56:05.0 Shenzhen Transit Station export security scan
2016-07-27 11:00:28.0 Shenzhen Transit Station export customs scan (domestic transit )
2016-07-31 22:05:34.0 Beijing Transit Station export security scan

2. May I suggest you read this for your country:
China Post Airmail Parcel Estimate Arrival Time
On this site:
http://track-chinapost.com/China_Post_Arrival_Time_Stat.php

3. May I suggest you read this also:
My parcel stuck in “Export Security Scan” “Export Customs Scan” for long time, how can I do?
On this site:

My parcel stuck in “Export Security Scan” “Export Customs Scan” for long time, how can I do?

Hope this help.