hello, I am 21 weeks along with a baby boy! on my 20 week ultrasound the doctor found a bright white…

hello,

I am 21 weeks along with a baby boy! on my 20 week ultrasound the doctor found a bright white spot on my babies heart. I have been looking at some message boards that claim this could potentially be a soft marker for downs syndrome....however everything about my baby is normal and I did do the DS integrated screening that came back as 1;10000 chance and all his measurements have been perfect. my doctor reassured me that she believes everything is fine, but I'm worried. I did do the Harmony blood test to make sure... any other moms have experience with this or been through this?