Due date change?🗓

Hey ladies!! 
How much did your estimated due date change from the time you found out you were pregnant to when you had your first ultrasound?! 
Based on period math, I am 5w 2d and due June 6th. I think I would currently measure around 4 weeks and end up being due the second week of June though. 
The first day of my last period was August 30 and I didn't ovulate until cycle day 18. 
Just curious to see how much it changes when you figure it out based on period math versus the actual measurement!