13 weeks and freaking out

Just hit 13 weeks today. I started having these weird pains in my pelvis, below my stomach. I really don't know how to describe what it feels like, maybe extremely light cramping. I have had two MC's in the past year, and the cramping I had then is not the same as what is happening now. Needless to say I am freaking out. This is how my last MC started, with constant cramping. The nurse said I need to eat more protein...  I go to the doctor tomorrow for my work up and ultrasound. This was the same appt when I found out I lost my first baby...so I am super scared.