They do not update tracking over the weekend. They don't even update tracking very well to be honest. Had the same issues when i ordered my MacBook Pro and that was when it wasn't in heavy demand. They compensated me by offering a free laptop bag for all the delays and wrong shipping estimates
Also, reading other threads i don't think people will be getting theirs early, infact someone had his expected delivery 5th of Aug and it still says NOT YET SHIPPED!
Check status every three days and save yourself an early grave with the stress.