terrified! didn't sleep at all

Jaclyn
So I went to bed last night, 5 1/2 weeks. My period like cramps had stopped a few days ago. I was woken up by a horrible pain. On a scale of 1-10 it was a 10. Sharp stabbing pain in my uterus that I was doing breathing exercises through because it hurt so bad I couldn't move. It happened for about a minute and stopped and never happened again. But all night I kept getting up to check my underwear because I swore I was having a miscarriage or something it hurt to bad. Has this happened to other people? What was it?