Fist ultrasound “size less than dates”

Hey mamas!

Looking to see if anyone had something similar and how it turned out.

I had an early ultrasound and I’m a little confused about the dating. Based on my last period, I should have been about 8w6d, but on the ultrasound the baby measured 7w3d (CRL about 1.21 cm) with a heartbeat of 156 bpm. The report said “size less than dates” and recommended clinical correlation.

They did see one baby in the uterus, yolk sac present, heartbeat strong, and everything else looked normal, just measuring about a week+ behind what my LMP would suggest.

Did anyone else measure behind early on but everything caught up later? Trying not to spiral and would love to hear real experiences.