I don't think that's the nub, tried putting up a different pic that I have but it says the files too bigIf that is the nub I can see pointing straight up that is 100% a boy
However could be cord or leg possibly!
https://www.google.co.uk/search?q=b...UIBygB&biw=1366&bih=643#imgrc=m551WAtf43gH4M:
It looks very similar to that which is a confirmed boy nub