Gender prediction based on nub and or skull theory?

[keraellis]

This is my bundle of joy at 13 weeks, me and my husband was surprised to see how developed he/she was and can even see the brain. Can anyone guess the sex? Its just a guess and I will update at 19-20 weeks.
16069

[myrainbowgirl]

boy

[hotdogz&boyz]

Little dude (is my guess). Congrats on your little one!

[beachbubs]

Leaning boy also :) congrats!

[fiszka]

Not really sure if I see a boy. Gender parts can be so much alike at this stage of pregnancy. Congratulations anyway and enjoy! :)