Hmm, sounds like growing pains as you said.
Or maybe something to do with the cervix? How far along are you again? I forget!

I'll be 19 weeks on sunday.

that sounds like something i had but i never figured out why it happened. i had a uti at one point and the feeling was similar to that quick pinch only with the uti it wouldn't stop, it was more like a burning in that area. my thoughts were that it was still uti, although i got checked for it and it had cleared, or just pressure from the baby's weight. i don't know! now that baby is so big i get poked hard in the bladder once in a while and i get a similar feeling.

i have also had pains like this in the crotch and butt area they come and go I am 31 weeks i was told by a friend it may be the cervix trhinning but who knows?

is it in yor lowere abdomen area? well below the belly button but above the vagaina area?

if so its most likely ligaments streatching. yeah it hurts and it happens to me alot
im 20 weeks 1 day