Low fetal fraction


A week ago when I was 10 weeks and 4 days pregnant I took the genetic blood test for chromosomal abnormalities.. today I got a call from the doctor that the results came in but she said I had low fetal fraction so I have to take the test again today . I took the test about 2 hours ago again I have to wait for another week . Has this ever happened to anyone ?? Am very scared and upset .. can this be a sign of anything wrong