Scared Out of my Mind!

I have been a nervous wreck since my 20 week scan. What should have been a joyous moment has been hell ever since. During the ultrasound, the tech could only find one Kidney. The one kidney she could find was also enlarged. Now, the Doctor said its possibly enlarged because there is not another kidney and it is doing the work of two. She went on to tell me that people are born without even knowing they just have one kidney, and that my son will live a normal life. Well, then the Doctor talked to me about an echogenic bowel. Meaning, there is a bright spot on his bowel. These two things she said are considered soft markers for Down Syndrome. There are possible causes too, none of which sound great. 
I'm awaiting the second round of blood work and now will see a specialist for a more detailed ultrasound. This may all lead up to an amniocentesis for a definite answer. 
My son could be completely healthy and all this a mistake or just have one kidney or other complications. Everyday that passes I wake up hoping this is just a terrible dream. 
Have any of you experienced this? Outcomes?
Please pray for us ❤️😢