Peeing on bed problems

So my 3 month old kitten the day i brought her home was a pro at using the bathroom. There was absolutely nothing wrong with her and she loved her litter box.  

But now, in the last 3 days she has gotten in the habit of peeing on my bed and my roommates bed.  I had flipped the mattress around to not have the familiar place exposed (up by the pillows) and she still went to the same spot and peed.  She consistently uses the litter box throughout the day so I am not sure why in the past 3 days she has become accustomed to randomly peeing in the bed.  

I have no idea how to train her to not do this.  I don't know if i should get a spray bottle and when she goes to do it and if it's infant of me, spray water at her, or what. I really need help. 

clean with a enzyme cleaner. also read this article http://www.thecatsite.com/a/cats-and-discipline-dont-mix

Until you get this resolved, your roommate might want to join the Rubber Sheet Brigade. Its a lot easier than having to soak the mattress in Nature's Miracle every single time, believe me!