extra something in with baby

has anyone had this happen...so i am 20 weeks an my ultrasound they said everything with the baby is great just there is a piece of something in there they didnt specificly say where or attached or not just that o have to see another doc an get more test to see what it was an if it could affect my baby in any way.

* also this is my second baby my first is two i had to have a d and c done to stop bleeding after plecenta wouldnt come out could it be related to that? i am just worried need help has anyone had. anything like this