Aih, I totally understand the worry lah, even when doctors say it's usually nothing, the "usually" part still plays on your mind kan? One of my mum friends had the same thing detected at her scan, and her baby was born perfectly fine, no issues at all, and now toddler is running around like normal kids do. Since it's stayed the same at both scans and everything else checks out okay, that's actually quite reassuring, but definitely worth having another chat with your specialist just to get their thoughts on what to expect at delivery and after, they can give you the most updated picture for your situation!