Is it normal for your period to overflow while you sleep?

This happened to me about one or two days ago. The night before it occurred, I had scratched at my panties to relieve an itch, but my panties weren't left askew from the contact. In the Morning, I got out of my bed and felt very odd. I put on my shoes and headed to the bathroom. While I was in the process of making my way to the bathroom I noticed that I felt curiously wet and I could feel something moving down my leg. I pulled my pants leg up to find blood trickling down my leg. I rushed to the bathroom and pulled of my pants and to my horror I found that there was dark period in random places. There were patches of blood on various parts of my leg and it kept dripping out of the side of my panties. I took my pants off completely and tried to wipe the blood off and then I sat down on the toilet. I pulled my panties off and looked at the pad. Somehow, my period veered diagonally of my pad, but I'm still baffled by the various directions my period took. Then to make matters worse, some of the blood got on the floor and the bottom of my shoe and I haven't been able to wear it since....

I've had my period since I was a child and after all these years, this is the first time that anything of this magnitude has happened to me! Is it normal?!