Just curious! Is it normal for my baby to keep measuring ahead?

Nomi

So my original due date is June 22. My doctor said he will not change it until 36 weeks. My 16 week ultrasound my baby boy was measuring June 16. I went yesterday for an ultrasound at 29w 3d and he was measuring to be here June 7th. He was already head down and weighing 3lbs 13oz. Is it normal to keep measuring ahead each time? Do you think I’ll have him before June 22? This is my first child so I don’t know what to expect!