missed miscariage symptoms?

Hello! did any of you had a missed miscariage but still had pregnancy symptoms? I have my first ultrasound in 2 days, i'll be 12+3 but i'm scared they will tell me my baby stop growing. I have nausea, sore boobs. But my belly isnt growing even when I lay down and try to suck in my belly I can't feel my uterus. am I worrying to much? This is my fourth pregnancy if you count miscariage (1 living baby).