Ultrasound Gender determination - skull or nub theory

[Taylorbrooke2]

Hello! I just had a scan at 13w3d and I am wondering what everyone thinks based off either the skull or nub theory! Thank you :)

[ksmom]

The first one is baby facing the screen and the next two the nub isn't visible.

[atomic sagebrush]

I'm not seeing any clues here. Sweet baby!