Just felt my right calf blow up! Though it only lasted for a few seconds, the pain was extreme. I've had this happen before, maybe a year ago or so, but not recently. Both times it's been when I'm lying in bed and start to stretch my legs. I can feel the cramp coming on and there's not a damn thing I can do but enjoy the pain. Hope it doesn't turn into a blood clot and kill me. If I drop dead, check out my right calf.