Oh I've been here and it is scary. Both of my AFP tests came back that each of my children had a 30% chance of having DS...both are fine. I think that if you're dr is not worried, than you shouldn't..however if you'd like to be 100% sure, go ahead and request an amnio..I had them with both of my boys (more so I could confirm and prepare for whatever the test said for when they were born so it was not a surprise on birthing day).
Also, with my second son, I bled in my 2 or 3 mth, can't remember which, but I actually ended up loosing a twin...I now have a healthy, rambuctious 2 1/2 year old.. it's scary going thru all of this I know.
Good luck
K.
Updated
I just found this on line
Echogenic intracardiac focus (EIF) is a small bright spot seen in the baby’s heart on an ultrasound exam. This is thought to represent mineralization, or small deposits of calcium, in the muscle of the heart. EIFs are found in about 3-5% of normal pregnancies and cause no health problems.
EIFs themselves have no impact on health or heart function. Often the EIF is gone by the third trimester. If there are no problems or chromosome abnormalities, EIFs are considered normal changes, or variants.