hi there, I was wondering if you could help me, I had my 12 week scan yesterday they said my baby was fine, but said it was bout 36mm which is small for the age of 12 week old, and have go back in 2 weeks to have it redone. but when i got home i realised the scan picture said 8.6cms, my sister in law had a scan same day and they said her 12 week fetus was 8.8cms and i really confused to why they want me to come back?