Harmony Test combined with 1st trimester labs/ultrasound

Hey ladies! Sorry for the long post, but I need reassurance. My first trimester screen bloodwork resulted in a 1:33 risk for Down Syndrome. The ultrasound came back normal with his neck measuring within normal limits..it was just the blood that gave me the high risk. I had also taken the Harmony test, which came back negative (1/10,000 risk for trisomies 13, 18, and 21). Then, in my second trimester bloodwork, my AFP level was elevated (3.12 MoM). At 20 weeks, I had a level 2 anatomy scan to rule out Spina bifida. His spine was perfect and he showed no markers for Down Syndrome at all. I have over 7 large uterine fibroids so the doctor said this could have caused the elevated AFP level. I had a Genetics consult and even though the Harmony came back negative, they wanted to perform an amnio to rule out Down syndrome, Spina bifida, and other genetic issues completely; however, I am currently 25 weeks and did not want to risk miscarriage, esp. after my last pregnancy resulted in a blighted ovum. One doctor said I didn't need the amnio if I was just concerned with ruling out Down Syndrome, but my high-risk doctor made it seem like there was still a possibility, although low, that even with a negative harmony result and no markers on ultrasound, something can still be wrong. I want to hear your opinions on whether I should just be content with my negative Harmony test results and my perfectly normal level 2 anatomy scan at 20 weeks. Also, I read that low AFP, not high, in the 2nd trimester can indicate Downs. I am just so confused and worried. Thanks, ladies!!!