Another scan at 18 weeks was done (baby scan is done every time we go for a monthly check-up) and once again our sonographer told us the baby's gender. C still wanted to wait till we do our full detailed scan.
Finally the day of our full detailed scan (20 weeks) at Fetal Medical Center came, and before we left the house it has been settled that what we find out today will be final.
Doctor checked the baby's head, hands, heart, tummy, feet and...
"Do you want to know the gender?"
"Yes, Doctor"

Mom, are you sure?

YES. I'm going to have a baby sister.