How long does it take to be delivered from the "prepared for ship" status?

Hi!
I ordered my 16gb Wifi IPad on may 8th and just now(14th), it turned to
"prepared for shippment" status.
How long does it usually take for apple to ship an Ipad and how long does it take to be delivered at my house?
I am leaving town on 21th so I need to get it by that time

Message was edited by: Henrypark