The ultrasound and the physician together cannot predict exactly how old the fetus is. They can be days off either way. Unless you know the exact day you conceived there is no way to tell. My ultrasound showed me due (spet 28th) 5 days before my physician given due date (oct 2). Anyhoot I am still preggo..Just waiting. Ultrasounds are normally more acurate than the phys dates but neither are exact.

Congrats on your u/s glad to hear everything went well!

Hi! I was just curious, if a sonogram gives you the gestational age of the fetus, would you count the weeks from conception instead of lmp. Thats why my sono was done in the first place because I didnt know my lmp. But I know the date of conception. Ive also heard that first trimester ultrasounds are accurate within 5 days of conception. Is that true?