"Origin post is preparing shipment" meaning of international delivery?

I ordered a phone case and screen protectors for my evo 3D on friday morning. Saturday I was notified it had been shipped. Since saturday evening the status of both tracking numbers have been "origin post is preparing shipment". when previous status's were Acceptance- China Post, and then Proccessed through sort facility- Shenzhen, and now "origin post is preparing shipment". How long does this part usually take from china- to kentucky (United States) via USPS First Class Int Mail.