I had very strong suspicions with this one, and I'll be able to tell you if I was right or not (in case people remember what my verdict on my 12w scan was lol) in 9-10 weeks
With Jae, I went back to the shots i got from my 12w scan, and it followed the girl 'rule', but i didnt know what that rule was at the time...
Both times the sonographer refused to even make a guess, or be kind enough to get some clear shots of the nub, so I had to play back and get the best pics I could, then uploaded to the in-gender forum to see what they said.