I've been on my period for a few days, and it was pretty normal for a while. Then, I started waking up in the middle of the night with the shivers, and extreme lower back/side pain. Walking usually helps this pain, but I've been much too weak to walk more than a few minutes at a time. This morning I woke up, and could barely move because the shivers were so bad. I felt extremely cold, but I could tell that my body temp was a bit up there. I managed to make my way to the bathroom and fill up the tub with water. It was as hot as I could make it, but it still felt luke warm. I've been drinking water, I've gone though a bottle and a half but I still feel dehydrated. I have a history of shingles, so originally, I thought it could be that, butno sores have appeared. Then joint pain started, in my hips, neck, knees and elbows. What could this be? Could I just be having a monster period?