Bleeding too much (TMI lots of blood, bloody tampon)

I woke up to blood all in my underwear and I went to take my tampon out and it was like this, all down the string and blood went onto the floor too. I've never been this heavy in my life I'm 21 and my periods are usually decently light. I'm a little scared. Is this much blood okay? My boobs had been more painful than ever before and I've been way more emotional and no cramps. I thought maybe I was pregnant because I've also been super nauseous but obviously not. I had put the tampon in last night just in case because I had light pink spotting. I'm a little wigged.