Had a scary ultrasound

I went in for my first ultrasound, I’m about 8 weeks, the heart rate was 173 and measured right around the same time, but my OB said during the scan she noticed the “nuchal fold” around the head was measuring a little large, she said it could be nothing but that she recommends me getting an additional ultrasound around 11 weeks to get it measured again to check and see, if it might mean a chromosomal abnormality, something like Down Syndrome. I have to now wait another 3 weeks for this test to see if my baby is ok, and I’m freaking out. Has anyone else ever had this happen and everything turn out ok????