I woke up one morning and noticed I had a bald spot about the size of a nickel in the back of my head. A couple weeks later now three more spots have popped up but they are somewhat smaller than the first one. What could be causing my hair to disappear in spots like this?

There are quite a few things that could be causing this actually. But one thing pops up in my mind. Could you have ringworm?

You should get this checked out by your doctor. It could be ringworm, or alopecia, or a number of other disorders, but only your doctor can tell for sure after an examination.