What would the doctors do?

I havehave been having contractions for days, I told this to my doc on friday and he checked me, and would really let me know much else, except that he" could get a finger in" and that that's normal for a woman going on her 5th child, and" to make sure I get right to the hospital if I have contractions" so I called the nurse a few hours later and asked what my dilation was recorded at, the nurse said 4 cm, 60% effaced. So... my question is now, A. Why didn't they get the to go into the hospital, isn't 4cm risky? And B. I have been having contractions all day today, but not but every 10 minutes, he said to head in at every 5. So. What would they do if let's say im a 5cm dilation with further effacement. What do you think they would do since im only 35 weeks... im guessing they wouldn't let me go home with a cervix that open right? So what should I expect.