Intense lightning crotch?

I've been having this so called lightning crotch for the last hour or so, but it's so bad it makes me jump. It feels like a joint cracking/popping accompanied by a sharp stinging sensation all through my vagina and pelvis. I'm 39+2 so anything to me is exciting but why wont this go away? Any other time I've had lightning crotch it's been once or twice and then gone, this is basically continuing every few minutes and making me jolt in pain every time. Help someone tell me it's normal