Miscarriage before positive test

I'm 25 and TTC. For all of the years I have had a period, I rarely have symptoms before I start. No cramping, my breasts are never different, I usually don't even know I'm going to start (I've always had irregular periods) until I see it. 
All of the sudden I was feeling nauseated, my breasts were super sore and I just felt differently. I felt like I just knew I was pregnant. I took a test which said negative. 
The very next day I had the worst cramps of my life. My sore breasts weren't sore anymore. And I was bleeding extremely heavy. My periods have always just lasted about 3 days from start to finish with very light bleeding. There were a lot of clots and it was very dark.. Almost black. 
I almost feel like I miscarried, but I never had a positive test... I don't know how else to explain it...  Any thoughts?