One sided cramping?!

Ivey • Due July 29th!
Hello fellow mamas! My name is Ivey! I'm 10 weeks along with my second child. A couple days ago I experienced EXTREME shooting pain in my lower left abdomen! It scared the hell out of me as I've miscarried before and I've heard of pain like that possibly meaning a ectopic pregnancy (the doctor noticed nothing of that sort in the ultrasound) I was told to rush to the ER ASAP but others told me to wait it out since I was not bleeding and going in for something that could be nothing would just cost me a bunch of money! The pain eventually subsided later that night but I was wondering if any of you other mamas have gone through this sort of pain, and if so, did you find out what caused it??? 
Thanks for the feedback!
Ivey :)