Membrane separation 11week scan

Smilie • Hello our first baby girl is on the way on the 22nd November 2015... Please be a sticky baby 👼 ✨BD to all
Hello ladies. So went for my 11week scan and baby was bouncing and kicking its feet like crazy and touching its face. 
To the right outside there was a wee tiny measurement of 0.2cm and she called it a membrane. Is that some sort of separation from the placenta?really worried my baby is in danger even though she said it an heel on its own and it's very small and the baby doesn't seemed bothered by it. 
Has anyone ever had this or does anyone know any info or advice or stories they can Give me?