Abnormally heavy period?

Ok so I usually have a heavy period, and it's very regular and the flow is usually the same each time around. I woke up this morning, and stood up. Worse than Niagara Falls. A huge waterfall down to my knees before I could even run to the bathroom directly across the hall. I cleaned up and put in a super absorbent tampon, and an hour and a half later I needed to pee. I found that the tampon had leaked EVERWHERE in my sweatpants. My period has never ever ever been this heavy. My stress levels haven't changed or anything or my exercise, but I have noticed I'm hardly ever hungry anymore so I'm not eating as much and I've been gaining a little weight. Anyone have a possible solution? Thanks in advance.