Measuring behind at 5w6d

Went in to my fertility clinic for a very early ultrasound today after a spontaneous pregnancy. I was tracking ovulation and temps and I believe my ovulation has to have been August 11 or 12 at the latest (which would put me at 5w6d or 6w0d today). They were able to see a gestational sac, a yolk sac and a fetal pole with a CRL of 2.0mm. They told me this puts me at more like 5w3d and of course I’m nervous about this. I know with such small measurements at this point there’s a larger room for error but I can help feeling nervous. Going back in a week to check on the growth.

Prior to this I had a beta of 1907 at 20dpo and 2934 at 22dpo (so those numbers didn’t double).

Has anyone had similar measurements? How did it turn out?