What is a nub? Nub theory

[yesmelord]

Hello!

Googled and looked at old threads where people post there scans and other people can instantly see a nub?

How can you tell it's the nub? What is the nub?

We had a surprise with DD1 but not sure if it would be easier to know the Sex this time around?

All I can see is spine and legs?

In a scan where you can see the legs, you generally can't see the nub. Remember that ultrasound takes a two-d image of a 3-d object. The nub picture is a slice seeing the mid part of the body. So if you can see the legs, generally it isn't a slice through the middle of the body.

That makes sense! I thought I couldn't see one! Thank you!