It definitely had to have been months (9+ at least) before Revenge of the Sith. We know that when Anakin came back after the Battle of Coruscant and saving the Chancellor, it had marked 5 months since he had seen Padme.
shareThey were conceived by the midi-chlorians.
shareEven though they look just like Earthlings, they are not, so the gestation period for them folks might be different than 9 months.
shareI think the Star Wars characters are supposed to be biological humans, with all our internal processes and flaws. Eating and sleeping like us, gestating offspring for 9 months, too many individuals displaying a destructive lust for power, just like us.
With zero explanation of how humans like us came to populate another galaxy, long, long, ago.
When?
Right after they bumped uglies last I would reckon
There was no father. She carried him, she gave birth, and died. She can't explain what happened.
sharePalpatine probably used the force to create Luke & Leia.
shareOr maybe Obi-Wan had an affair with her since the previous films imply affinity between the two and Obi-Wan comes to their house without Anakin knowing, with Obi-Wan being Luke’s dad as the real twist.
shareIf that were the real story, who could blame Padme?
Young Obi-Wan is much more attractive than young Anakin!