Ultrasound at 4w3d

Maria • Happily married. #1 baby due June 2022. ❤️ PCOS. Bicornuate Uterus. Chemical Pregnancy in 2015. 🌈

I know its too early to get an ultrasound but my doctor wanted to make sure it wasn't ectopic. I know some ppl at this stage dont see anything in the uterus but I was happy to know there was a cute tiny blob in my uterus at only 4w3d. No ectopic, thank God.

But I'm confused with the readings. Can anyone explain to me what exactly is the size of the gestational sac?

This is my first pregnancy so I'm totally clueless right now.