Two, I had one last night that I flipped out on the check in lady cause they didn't have the right u/s scheduled for me, then got scared I had done something to the baby...I was livid in my dream. But nothing directly related to something actually happening to my child once they are here. I will say I think that it is normal though, and I also think it's possible it could be related to your last pregnancy.
My mom said she used to have horrible dreams about someone coming and doing something to me when I was baby. Then when I was here the dreams got worse and she would wake up terrified and constantly checking on me. I'm obviously fine, so try not to let your dreams play with your head too much. But I think we all have dreams, thoughts, etc. that scare us. It's normal, we're going to be parents, and there's nothing that none of us wouldn't do to protect them. I have a million thoughts running through my head...what if this happens, what if that happens. I actually expected the lady to count all the fingers and toes on an actively squiggly squirming baby to make sure they're all there today. I know it's hard to just stop having these dreams, but maybe talking to someone will help relieve some of the stress you're feeling.
Hope everything goes well at u/s!