I'm 31 weeks gone and last 2 night was abruptly woken in my sleep by the most painful thing I have ever encountered - leg cramp. It was really scary how painful it was, my DH (darling husband) massaged my leg (calf) also placed a pack of ice and I gradually was able to stretch it, but it still hurts a bit..

Has anyone else experienced this? Any tips for preventing them and why they occur?