Has anyone ever had this period problem?

Olivia
I missed my period by a week and a half. Randomly yesterday i started feeling cramps and just about less than a minute after, it was like someone turned on a faucet! It just came flowing out! In 1 second i had bled through my underwear and pants! And in 5 minutes I bled through a pad! My cramps were so extreme I was in tears! And at work I nearly passed out! This morning when I woke up, I was not bleeding at all and I haven't bled all day. Although my cramps has still been extreme. I thought I had miscarried, but concidering im not bleeding anymore I thought maybe that wasn't the case. I'm really worried.  I'm calling my dr tomorrow but I just want your alls opinion! Has this happened to you before?