It it does really depend on if you plan on having a c-section or she playing having a naturally and also depends on your due date..my first son he was literally born 3 hours before his due date.. that's because I walked my butt of the night before...all in all I was in labor for 17 hours, I'm counting from when the contractions started before I went to the hospital...my Dr broke my water and about 3 hours later my 8.6 lbs baby was here lol. I was sooooo scared, but your doctor when the time comes will know what to do..my first pregnancy was amazing.
Don't be afraid. It helped me to remember that every single person on the planet got here in basically the same way and its pretty much worked out for thousands of years. Giving birth is incredible. If you wait until you go into labor naturally, you just go to your hospital's L&D area and check in. They take care of you and they contact your OB for you. Unless you know your OB is out of town or something, she'll be there, and there will always be an oncall ob available too if needed.
When it comes down to having your baby,if you choose c-section then you choose a date to have you son. If you choose to have w natural birth... It's a waiting game more or less. Though every pregnancy is different it is best that you ask your Obgyn. I hope this helped.