I'm Really Scared

I have a follow up ultrasound on Monday. 9:30am. I am terrified they won't see a baby again. I keep reading all this stuff that says you should see the fetal pole at 6 weeks. I was measuring 6weeks, 2days. They said everything looked normal, except for the lack of the baby. I've been trying to put off thinking about it all week, but I can't say it hasn't been affecting me. I keep trying to prepare myself for the worst, and in that, all I think of is the worst.