If it is a scheduled RCS, most doctors don't want you to labor beforehand as it can complicate the surgery-the baby's blood pressure can be affected, the baby can descend too far and need to be pulled back up, etc. That's why most RCSs are scheduled for 39 weeks-so that the risk of mom going into labor spontaneously is limited.
This. My doctor perfroms RCS at 39 weeks or when you go into labor if it is before that. In my case, however, I am a candiate for VBAC, so he said we can scheule the RCS at 39 weeks and try for a VBAC if I go into labor before that if I want to. Talk to your doctor about your options.