Need reassurance.

I'm am SOOO worried there is something wrong with my baby. I've experienced severe cramping for the past few days. Then a little earlier I felt this horrible sharp pain in my uterus it felt like someone stabbed me and ripped me open. After that I've only had dull uncomfortable aches since. I'm very concerned. My last ultrasound was 6 weeks and I'm 11 weeks 6 days. My bestfriend just suffered a horrible miscarriage at 6 weeks. I just got a bad feeling. I have an appointment tomorrow at 1:45, hopefully an ultrasound. I'm just asking for stories, or prayers.