everyone is different. I got it super early in my pregnancy like 5 weeks or so. but very rarely.

When does it usually start?

nope lol. and I know. it'll happen to me if I'm standing and it looks like I just got punched in my nonexistent balls

oh my gosh it was such a weird feeling. Will it stop happening after awhile? lol @emily18234

lightening crotch lol. you'll see it mentioned on here a couple times a week. totally normal