Pain during sex ?

So hopefully nobody will bug out when I say this but sometimes when I’m having sex with my boyfriend something will happen and like I’m not sure what but my body will cramp up like I get a sharp pain inside my vagina and I cramp up and can’t move. One time this happened with him and it was so bad he had to carry me downstairs to my mom and tell her what happened 😩😩😩 it was REALLY embarrassing and she has no idea either .

It doesn’t happen all the time but when it does I’m miserable. And when I do have sex I’m like terrified it’ll happen again so idk what to do