Could I be miscarrying?

So, I started spotting 5 days before I was suppose to have AF. It was a dark brown, kinda mucous looking discharge. I was hoping it was implantation bleeding. Well today is day 2 and I have been bleeding heavily. More than I have ever bled before. I am soaking through super tampons within 45 minutes to an hour. And a couple times (tmi) the blood looks like clots. Like stringy, mucousy blood. And the cramps, oh my. These cramps are horrible. Way worse than period cramps. I need advise! Anything helps! Thank you!