How did padme amidala become pregnant?
Padme Amidala does not have a middle name as far as we have been told up to this point. No-one has ever given her one. Her full name, however is Padme Amidala Naberrie Skywalker. Naberrie being her maiden name, and Skywalker her married name, while Amidala was a name bestowed upon her after she entered the political arena, known as her 'regnal' name.
Padme' Amidala was the Former Queen of Naboo, Galactic Senator, and secretly married the troubled Anakin Skywalker. When Padme' learned of Anakin's chose to join the Dark Side (while she was pregnant with Luke and Leia), she was devastated. She died (just as Anakin had foreseen) in child birth because she had "lost the will to live".
Padme Amidala (a.k.a. Senator Amidala) was only known as Queen Amidala in The Phantom Menace. And she wasn't murdered: she died in Revenge of the Sith. When Anakin turned to the dark side, Padme was so devastated that she lost the will to live due to her heart being broken. But she managed to give birth to Luke and Leia before dying.