Period issues

Hey guys, this may be descriptive. But I started my period a day early, which happens sometimes..lately I've been starting a day or 2 late. But it was a different pain that woke me up yesterday and I knew I started. It was the center of my lower abdomen. It felt like a knot like I had to use the restroom. I bleed alot yesterday,which I usually don't beveled alot until day 2. Well day 2 I woke up went to the restroom and there was so much blood that my tampon literally just feel out..I don't think I've seen that much blood before. I've had back pains today and yesterday along with a sick to my stomach feeling. I've had to change my tampon several times today. My friend has me worried that I may of had a miscarriage. The pain had actually is manageable as long as I sit down. Should I be worried about a miscarriage or other issues?