I have ordered quite a bit from China and parcels sent by EMS. Seller can give you a tracking number but that does not mean it has been posted. Sometimes there is a delay of 1-3 days before tracking information comes up. I would try the seller and find out what is going on and if the parcel was posted.
Always buy through company that holds money in escrow until you receive goods and OK release of funds.
Hoe this helps :)