Im absolutely freaking out calling all moms for help, soft marker

Quad screen was negative, about 1 in ten thousand chance of downs and then I had my 20 week ultrasound and they found an echogenic heart focus my doctor told me not to be worried because it is a very common thing in healthy normal pregnancies but that it also could be a small marker for Down's syndrome but that combined with my negative quad screen and everything else looking perfectly fine on the ultrasound that I should not be worried because it is a common occurrence and typically turns out just fine and resolves on its own, but I'm kind of freaking out so if any of you Mommy could share your experience with this if you have experience it would be much appreciated