I have 3 boys and am 14 wks 5 days. Your nub looks similar to my nub at 13 wks 5 days. Mine is straight but curls up slightly at the end. I got a few girl guesses and 2 slight boy leans. I sure hope they are girl nubs! Here is mine.
I think your nub have a bump on it and not curled up, so looks like boy?Hope Im wrong!
(sorry to reply here)