I don't know trinity
I do know, that any doubt - even something teeny tiny, they prefer to get the consultant (or a more senior sonographer) involved.
My cousin (whose husband is an eminent neurologist) had to go back 3 times for scans because they thought they could see an anomaly in the baby's heart. She was in pieces for weeks but it turned out to be nothing and as the baby grew, they managed to get a better picture.
I know it's impossible to say 'don't panic' and a week probably seems like an eternity but maybe all they need is a more detailed scan to see what's going on.