kinda scared..

I've never had a baby before so I'm always reading about different symptoms and just different things in general about what i might feel while I'm pregnant. I just read about "missed miscarriage" and I cried because I'm scared when I have my u/s my baby won't be there.. I haven't had many symptoms in like two days besides my back pain so it scares me. Does anyone know if there's at least one sign to a missed miscarriage?