UK 🇬🇧 how accurate is gender at 12 week scan?

So I’ve just had my 12 week 6 day scan and the man doing it said to me did I want to know gender, to which my reply was along the lines of OMG YES!

I didn’t think he would be able to tell me today, but he said it was a girl!

He said it’s not 100% but something along the lines of there’s a bone or something which if this ‘bone’ is parallel to the spine - it’s a girl, and if it’s sticking up it’s a boy.

Now I’m MEGA EXCITED to say the least as I hoped and prayed it was a girl - but now I’m worried as he said the theory is not 100% and they’ll be able to tell me at the next later scan.

I don’t know whether this theory is more correct in its research rather than wrong, which I’m assuming it should be or they wouldn’t be telling pregnant women the sex at 12 weeks.

Would you be excited or worried?

Or is this something the sonographer has to say to cover himself if he’s wrong and that I’m actually being silly. 😩

I want to enjoy the news of my baby girl.

❤️❤️❤️❤️❤️