When To Leave Home

My family is famous for 4-5 hr labors and almost no pushing time. With my first i was induced (unnecessarily i believe, now) and I've never experienced healthy full term spontaneous labor. My home birth was thrown out the window for various financial and insurance reasons and my only option left is the hospital. Luckily, I adore my dr this time, but unfortunately I'm terrified I'll not make it in time- or worse- I'll be wayy to early! My plan is to labor at home as long as possible and head in once I'm 7cm. If i get to the hospital and I'm less then 6cm, I fully intend to leave unless things progressed to that point very quickly. Im not convinced ill be lucky enough for a quick labor! I'm pretty okay with accidentally giving birth at home as my doula is also being certified as a midwife and I've got a very healthy uncomplicated babe, this doesn't scare me at all other than I know my SO well call an ambulance and I'll have to insist they leave me alone unless i need help or they may look at baby but not leave unless there is an issue. What i am terrified of is giving birth in the hospital lobby/hallway/lawn. It mortifies me becuase it's a freaking hospital and im scared my SO will be shoved out of the way and I'll be man handled onto a gurney with a baby crowning or hanging out of me and seperated from everyone.

Anyone have any good advice or encouragement? I'm scared this fear is going to leave me at the hospital too early or having a stressful unplanned home birth. :(