Vibrating ovaries?

So really weird a couple days ago I was just going through my daily routine and all of a sudden it felt like my left ovary was vibrating. Not like a muscle spasm more like if you had your phone on vibrate in your purse and felt it go off on you or a tickle. Well it happened again, this has never happened before these past 2 incidents. I'm pretty sure I'm not pregnant due to AF arriving yesterday. I was just wondering if this has happened to anyone else and if they knows what it could be. Once again this has never ever happened before these isolated incidents.