It does depend Jols, 12 weeks is pretty standard for the NT I think - but the place I go to says that anything from 18-20 is fine for the morphology one, so it might just be best to check. They will probably tell you when you book in anyway!!! I know the place I go to doesn't require a full bladder whereas some others do!! Go figure!!!! I just realised how close to Valentines Day you are due!!Awww how exciting hun! Good luck with it all!