Shocking check up!

At my check up Monday I was shocked to learn that I am already dilating. 
35 + 2
3 cm dilated
75% effaced
-2 station
3rd baby
Contractions here and there. 
I am 30 minutes from the hospital but husband travels for work.
Our doctor doesn't think I will make it to 40 weeks. She will not stop labor from this point forward. I am a little nervous because I have never delivered this early. How do I prepare for a possibly early baby?