I got my VON a couple days after ordering. I messaged my Dealer every week to 10 days until I got my VIN. I finally got my VIN 5 weeks after ordering.
You get your VIN when they are actually building the vehicle. The time between ordering and when you get your VIN, they are collecting parts and making sure they have everything (or at least most everything) prior to building.
As soon as I got my VIN, I tracked it and it was stating "it was built, but awaiting installation of equipment" and then gave me an estimated delivery date (4 mo mark - which is typical this early in the order process).
So basically, it will take some time to get your VIN. I would say don't pester your dealer more than once a week. But go by what they say. If they say "you'll have it in 2 days," then call back in 2 days. That's what happened to me - my salesguy was ill-informed and assumed a much faster turnaround than what it is - so I called/texted him whenever he said to call him back no matter how optimistic and unrealistic he was.
Good luck and welcome to the waiting game!