What Causes Heavy Vaginal Bleeding And Shaking?

Im 18 and a couple months ago I was late on my period by 3 weeks. I thought I was pregnant, so I took 2 pregnancy tests both negative. One day I woke up and I was bleeding really heavily and I thought it could be my period because its always heavy. But after a couple minutes I felt like I was going to pass out, I was throwing up, shaking, and sweating. Could it have been a early miscarriage?