1. There is a few people here from USA in the same situation has yours. But they are expecting parcel to JFK and not Chicago.

2. I only can assume that the parcel departed late from China to USA because there was a National holiday all week from the 01 - 08 Oct. So basically mail piled up at Airport warehouse.

3. When they started working, then only a certain amount of mail bag can fit into the cargo area with the passenger suitcases.

4. It could also be at ISC Chicago, there was to many parcels arriving at the same time.

5. But according to the tracking the parcel is fine. you just need to continue to track your parcel on the USPS site for any movement. Really hope it's going to be soon for you.

Hope this help.

1. This is the tracking of your parcel:
China Post Register Air Mail Tracking System
Parcel No.RJ871816624CN tracking result
2016-10-10 14:56:37.0 宁波city parcel 局 received
2016-10-10 16:19:39.0 宁波city parcel 局 customs scan
2016-10-10 21:18:10.0 leaving 宁波city parcel 局 ，next station 宁波center
2016-10-11 22:27:36.0 Shanghai Transit Station export security scan
2016-10-12 14:24:16.0 Shanghai Transit Station export customs cleared
2016-10-12 23:46:00.0 arrive Shanghai Int'l Airport
2016-10-13 03:16:33.0 leaving Shanghai Int'l Airport going to next airport/seaport

2. Your parcel is On Route to Malaysia, may I suggest your read this:
http://track-chinapost.com/China_Post_Arrival_Time_Stat.php

3. Your parcel is fine you just need to wait for it. You might be able to track your parcel on the Malaysia Post site when the parcel will be scan. I was not able to connect to the Malaysia Post site.

Hope this help.