What does it mean for Trisomy 18 levels to be up?

Has anyone has the quad test and MSS Trismony 18 levels were up? My levels were 1:500 and the standard range is 1:100. My doctor said she would call me if anything was bad, she hasn’t called me. I seen the results on my chart. I’m freaking out. I’m going to call her tomorrow to see what that could mean. Has anyone had this before?