If it continues I would see a doctor. Just to put your mind at ease. I'm sure you'll be ok. When you wake up tomorrow try to do something busy asap and see if it still happens. You could have a weird little virus that will pass in a few days. Sorry I'm not much help. I've never experienced this personally.
This started happening to me about a year ago, but it happened when I couldn't sleep due to a health problem. When I researched it this was most often a symptom of anxiety, but if you need reassurance you should see your doctor.
The first thing you should do is get your Thyroid levels checked. Hypo Thyroid can make you shiver violently. Good Luck!
My whole family is experiencing nausea, diarrhea. I was watching my 1 year old cousin after she woke up earlier and noticed she was shivering in the same manner I had been (its not happening to me anymore). I'm assuming we're just all sick with something.