I saw somewhere on here once that Ep III takes place in five days

Yeah DarkC is right, in the beginning Padme is kinda normal shaped and at the end she is highly pregnant. It must take some more time to grow a belly like that than 5 days. So I think it must be something like a month or so. We just dont get to see every day.

No, it's 9 days.

And she kinda had to hide the fact that she was pregnant, no?

Yeah, I think it said in Star Wars insider (and you can see) that Padme's clothes were, as I said previously in this topic, designed to hide her pregnancy, they all were big and came out and poofy and all that.

If you use Coruscant as a basis than you'll find that it is infact something like 4 days - but the scenes recorded after Threepio's last dialogue are probably a few days later

Day 1 - Space Battle/Crash Landing/News of the Baby/Anakin's Dream.

Day 2 - Anakin consults Yoda/The Briefing with Obi-Wan/Appointed to the Council/The Gunship Scene/Anakin and Padme-Veranda/The Opera Scene

Day 3 - The Council Meeting/First wave of Kashyyyk Battle/Obi-Wan leaves for Utapau/"I feel lost."/Locating Grievous/"I Sense a plot to destroy the Jedi."/Sidious reveals himself to Anakin/Destruction of Grievous/The Terrible Truth/Padme's Ruminations/Mace Vs Palpatine/Birth of Vader/Anakin's Betrayal/Anakin leaves for Mustafar

Day 4 - Yoda, Obi-Wan and Bail return to Coruscant/Birth of the Empire/Slaughter on Mustafar/Obi-Wan, Padme-Veranda/Padme leaves for Mustafar/Obi-Wan Vs Anakin - Yoda Vs Sidious/Immolation Scene/Padme Dies - Luke and Leia are born/Vader rises

Day 5 - Yoda, Bail and Obi-Wan discuss the future

the last four scenes were probably days later, we'll never know

Umm, boys, Padme's carrying twins. Ever seen a pregnant woman carrying twins? Their bellies are HUGE, even bigger than 1-child pregnancies. And they tend to get big fast, early, and get even bigger later. And a lot of them are on bedrest during the last weeks.

Now if Luke & Leia were pre-term, say 5-6 months or so, Padme's looking fine.

Well when you first see her it doesn't look like shes pregnant, and at the end it does so I would say 7,8, or even 9 months.

There's no way to cram all that stuff in 4 days, Stun. It's 9 days.

I thought she looked bigger during her talk with Obi-Wan (when he asked her if Anakin's the father), than in her Mustafar outfit. Maybe they used the wrong belly pillow! She also ran pretty fast on the landing platform for a woman about to give birth!

Haha.