Is Sneak peek accurate????

Kylie • Giovanni born 10-08-2021👣 Due 1/27/2023💗

I took my sneak peak last saturday i would have been 6 weeks 2 days since my missed period. My baby is measuring 6 weeks 3 days today but they barely could find her because she is so close to the gestational sac edge, i am suppose to be 7 weeks today. Does sneak peek go off ur LMP or what ur baby is measuring.

I would think still accurate every baby is gonna grow differently even if i am still 7 weeks along???