Heavy Implantation Bleeding or am I going crazy?

[Mommy2Be2014]

Hello, I'm new to this site. I've been having early signs of pregnancy for about three weeks now. I.E.) Itchy nipples, nausea, headaches,heartburn, I've been having cravings for things I don't even like, and I've been running fevers off and on. About two nights ago I had a really bad cramp. It was worse than when I had an ovarian cyst rupture. Today, I wake up and I'm literally gushing blood which is a dark red/brown in color. My AF isn't due until Feb. 28th. I've never been early or this heavy without a little bit of lightness before it became heavy. I took the first pregnancy test about three weeks ago when I first had the symptoms and then I took one yesterday and they were both negative. I have a friend who took six pregnancy tests and they were negative, so she went in for a blood test and she was pregnant. I'm hoping that I could be pregnant but with the amount of blood this morning I was wondering if anyone else has had this and still had a healthy pregnancy?