Down syndrome? Please answer

For those of you that have had a child who has Down Syndrome. What were some markers found on the ultrasound? My doctor has said not to worry because only one soft marker has been found (Echogenic intecardio focus). Everything else is normal, his kidneys, his nasal bone, brain everything else is good. Still can’t help but worry. FTM here as well.

-I have not done any blood work, in the beginning I figured I wasn’t at risk. But now that I am 25 weeks, This baby will be coming regardless. (I hate to say this but I am not physically or emotionally ready for a child with special needs) but figured if I take the blood test and it is positive that would make the rest of my pregnancy miserable and I would not be able to focus on anything else.