If you are planning on a scheduled c-section, what week?

Melissa
I'm currently 17wks with frat twins and I'm trying to get a feel for what others and their doctors are planning as far as what week of pregnancy to due a scheduled c-section. With my singleton (12 years ago) there were problems and almost had to gave an emergency c-section, so with these twins I want to be safe and have a plan up front.