MaterniT 21 plus positive result

Has anyone ever gotten a false positive from MaterniT 21 plus or similar NIPT screenings?? My doctor called me today with my results and Was positive for Trisomy 18. It was absolutely devastating to hear and when she told me to diagnose for sure I might want to consider a procedure that has a *risk* of miscarriage it just broke my heart. I’m 11 weeks and 4 days today. Just wondering if anyone had a positive screening for a chromosomal disorder that turned out to be false?