Yolk sac measurements

Hello Mommas, So I had my 2nd transv yesterday with an OB, everything seems fine. But today I have my regular check up with my OB, so she have some questions why the measurements of my yolk sac seems large. It measures 0.62 cm and she mentioned it's considered as large. BTW, I'm 7w6d preggy. If you have any information about this kindly spare some. Thank you and stay safe. ❤️