Please can someone explain the nub theory to me?

[iloveyoubutilovememore]

So here’s a scan picture from when I was pregnant with my son four years ago. Is this picture quite unclear because I can not make out where/what the nub is? Ive just had a read online and from that this nub looks more like a girl than a boy? I’m pregnant with #2 and want to be able to get it more by the time I have my scan!

It's my understanding it's that horizontal white line on the far left - on your photo it's elevated slightly (ie not completely horizontal) which indicates a boy

Hi, I’ve attached my private scan at 12+3 along with the results from when I sent it to the nub techs. The nub was really clear on my scan and apparent if the angle is less than 30 degrees you’re more likely to have a girl and above 30 you’re more likely to have a boy.

When I had this scan the sonographer actually guessed the baby would be a girl (yet to be confirmed) and when I asked her if she was using the nub theory to guess she said it’s not so much the nub theory she looks at ie the angle, she looks to see if the line from below the cord going down the nub is “smooth”, if it’s a straight line down it’s likely to be a girl because girl parts develop lower down whereas boy bits develop a bit higher up so you’d expect the line to not be so straight or something like that anyway I’m probably explaining it all wrong. But she did say it’s an educated guess at this stage. I’ll be going back in just over a week to see if she’s right!

The nub theory for my last baby was right, he had a ‘boy nub’ and was in fact a boy!

Following as curious.