Being so fertile that a man could look at you and you get pregnant. Falling for the advances of an ex and getting pregnant from one brief unprotected dalliance. Being young and foolish and so unlucky as to get pregnant every time you have unprotected sex.
It is said of the situation where a person has the bad luck to make contact with his testicles against an undefined surface or object, intentioned or not.
Given the nature of the word, it is more appropriate to design cases where the interaction is made with a moving object, for example, a ball.
Although it is extremely painful for the victim, it tends to be considerably funny to people who witness it.
Today in the baseball game the pitcher took a nutshot; the baseball hit him in the nuts.
Man, I just watched the funniest nutshot video ever.