Period from Hell or another miscarriage

Darynn
I've been on my period for 13 days now and it's been heavy 90% of the time. I have cramped so bad and also have had contractions, so I'm leaning towards another miscarriage. If that's the case, I didn't even know I was pregnant, I definitely don't know how far along I would be. 
I have bled through the super tampons, heavy flow pads and messed up 4 pairs of underwear. Today I bought the Diva Cup and have no idea if I'm even using it right, let alone if it'll contain this crazy flow. If the bleeding doesn't subside by tomorrow I am making a doctor's appointment. 
Has anyone else used the menstrual cups? Do you like them? Do they leak? How big is the "gross factor?" Do they hold fluids well all day?