The genital tubercle or “nub” is fetal tissue that can build into a penis or perhaps a clitoris as the pregnancy progresses. Nub theory says if you can find a very good evaluate this nub on an ultrasound, you might be able to identify the sexual intercourse of a fetus https://nubtheoryaccuracy66654.mybjjblog.com/baby-nub-theory-an-overview-40724217