I am asking b/c when i was pg with my DS, the photos from the scan said "y" on them (from the 8 week scan)and my scan photos with this new baby (at 8,12 and 20 weeks) also say "y" on them - so i wondered whether the "y" meant it was boy (ie x and y chromosome)
apparently there are two dots on a scan and you are supposed to be able to tell by how far apart they are. if there is a gap between them, it's meant to be the ovaries. this theory worked for dd and is correct for this pregnancy too but don't know if there is any real truth behind this theory. sorry
The NHS coudlnt tell on either my early dating scan at 7 weeks, the 12 scan or 20 week scan! So it really does depend, I ended up going private and paying for another scan at 24 weeks to determine the sex.
With a girl, there are 3 very visible lines and obviously no boy bits! The 3 lines were very visible at my 24 week scan. I think the NHS probably could have seen at the 20 week scan, but the baby wasnt in the correct position.
I would say that there is no way you could tell as early as 8 weeks.