2 Harmony tests came back inconclusive

What the heck does that mean? My first Harmony test was done at 11 weeks 1 day. It came back as insufficient data. I did another one through another lab at 12 weeks 2 days and that just came back today as inconclusive or insufficient data again. I'm starting to freak out. Does anyone know what that means? Do I have to do an amnio this time? The nurse that called me told me that they will just do an ultrasound on my next appt. How accurate will that be in screening for diseases if I'm only 15 weeks 1 day during that time? Has anyone gone through this? I need opinions, suggestions, assurance? I'm starting to panic and stress right now which I know isn't good for the baby.