Hopefully these photos will upload. I have 2 showing the nub (which I have rotated to try as the baby was tilted with the bum up in the originals which I think makes it harder to judge) and one where I can't see the nub but shows a good view of the head if anyone is good at judging by skull shape.
I can't work it out from the photos. I have been guessing boy and DH is guessing girl, but we'll be happy either way.