Belfie you might find that youare on the thome stretch with the insulin doses. Most people find that their insulin requirements tend to level out at around the 34 - 36 week mark and some even get a small decrease...if you get a big decrease however please let your dr know as this can mean the placenta is startign to break down, something that is also a little bit more common in GDs and Ds in general. All in all though I would say you are right on track...good stuff!!
Sizing scan are usually done on D patients but just be aware that they can be out be out by as much as a pound and if you are prone to have to big baby it my be genetics not D and vice versa so a grain of salt is my advice with a sizing scan (unless of course they tell you you are having a 13 pounder or something!!) hehe......