When Anakin first meets up with Padme, he seems surprised to learn that she's pregnant, despite the fact that he just pressed her body up against his (and he must have felt her pregnant body). Now I interpreted that apparent anomaly in that she had learned she was pregnant, but had not yet begun to show signs of it, in the early stages. Now later in the movie her belly becomes more and more prominent, so we could assume time has passed. I'm no expert on Obstetrics, but wouldn't this progression of her pregnancy put some necessary limits on the time frame of the movie events? Obviously I'm talking SOD here, because the makeup/costume department could have screwed up or Lucas could have just said "good enough" (all his kids are adopted, so he'd have had to do research on the whole thing anyway, and movie audiences are used to the fudging of realism in this regard).
Were the twins premature? Some have pointed out that the babies don't look like newborns. But it's also been admitted that the vast majority of movies don't show babies as they would look when first born. They're normally cleaned up and much older, since it would be much more difficult to film a real newborn for a movie and put makeup on the baby, etc. Women giving birth in the movies typically just sweat and scream a little bit and the babies are born in what seems like a few minutes at most, when in reality they can go into labor for many hours and go through all kinds of emotions and such. Of course we don't really know the extent of the futuristic technology of Star Wars affecting human childbirth, but still.
And of course with digital technology Lucas could have done a lot more for the sake of realism had he wanted to. After all, he digitally doubled one real baby and apparently CGed the babies into Ewan McGregor's arms too (from a previous take or another person holding the baby) supposedly.
Is the official timescale of ROTS (if it exists) create a problem with the progress of Padme's pregnancy?
I'd like to hear some thoughts, and if this is all spelled out in some book I haven't read, please be so kind as to enlighten me with the info so I can go read it and feel like an idiot again.

Thanks!