Re: 3 days without pain pills and having leg pain when laying down.
You may want to try sleeping on your side with a pillow between the knees and have them slightly bent as though you are going to pull up to the fetal position. The pillow helps to align your spine and relieve pressure. Another position that my spine surgeon recommended right after surgery, in order to reduce pressure on the back, is to place 2-3 pillows below your but at the back of your thigh so that you have your legs on the pillows pretty much as if you are sitting in a chair. That position while lying down really worked for me at that time. Doesn't work right now while I'm healing from a major fusion, but the side works well.
Hope that will help you when the pain hits in bed.