Measuring 2 weeks behind

Allison • 25 years old, 2 miscarriages in ‘15 & ‘16. Married 💍. 💙 KJS 6/30/18 💙 BBS 4/29/22

My fundal height has been about a week behind for a month or two now, but now at 37 weeks I’m only measuring 35. I have a growth scan on Thursday, but I’m just wondering if maybe I’m measuring differently because the baby changed position/ is lower now? Or is that not a thing? Hoping he’s growing okay in there.