Once the parcel leaves China, nobody will scan it again on China Post's behalf until it reaches the destination country. Read here: http://track-chinapost.com/?p=669

Historically, Vietnam takes 17 working days on average and sometimes as long as 22. You're at 16 now. Once it reaches Vietnam, VNPost will scan it and it'll show up in their tracking system. If things are on track then that should happen within a week or so, hopefully not more than 2.

No problem. And...really, It is somewhat absurd, isn't it? Especially when you consider that a direct flight from Guangzhou to HCMC takes something like 3 hours gate to gate? Sadly, parcel post doesn't work that way, not even like private couriers where there's a somewhat-tightly coordinated network to keep things moving. The trade-offs necessary to make parcel post cheap also make it slow. Much of a package's time is spent waiting: waiting to be sorted, waiting for a shipping container to fill up, waiting for airline space to become available, waiting to be unloaded, waiting for customs...