Does this only update when the status changes from pending to approved?.
--> No, DOS update the site with the documents received and the status remains "Pending". What I heard is that DOS normally updates the site within a week after recieving the documents. In my case DOS updated after a week with a week earlier date when they recieved it.
If I were you, I would call VA and find out how they sent it. Hopefully they sent it via some trackable means, like Fedex. Get the tracking number and check that out first.
Good luck... and post your update here how long DOS is taking these days.