What is this nub theory? I'm confused..

[mamarach26]

I'm 23 weeks now and only got a picture of the face with my 20 week scan. I did get a full body one with my 12 week but the baby did not want to be seen. I think I saw boys parts on my 20 week one.
This is a bad picture but tell me what you think!

I see a baby, how exciting!

(No idea what nub theory is, either. I thought I saw boy bits at my 20w scan, too. Had a girl)

I've seen the nub theory everywhere but I just don't get what I'm looking at! I'm not finding out the sex. I had a boy 2 years ago and I have a feeling this ones a boy too!

This is my 12 week scan picture (now 32 weeks) and the nub is the white line protuding from baby's belly. It is said that if it is raised up to a certain degree from the base of the spine it is most likely a boy and if it is level with base of spine, a girl. We are team yellow but apparently by the nub on my scan I should be having a girl. I wouldn't take it for gospel though as it's supposed to be a bit of fun

Congratulations and good luck!
I'm just so confused with it all, think I've been looking at the wrong line so what would mine be?

I think girl- based on the head. Not sure I can see a nub on that scan pic though? (Not a professional!)

I'm not sure as there are a few lines on the scan and it's difficult to tell but if I were to go by the shape and look of the baby I would say boy. Saying that I have 2 ds and a dd and was wrong on all 3. I am rubbish at the guessing part

I don't know why I'm guessing so much as I want a surprise! This is my 20 week one, I've heard about the head thing too. Is it when it's more rounded it's meant to be a girl?

I think that's a girl too. Am mostly wrong but looks like a girl to me

I've not even thought about girls names, I just have a feeling it's a boy! I'm carrying low again