they will admit you once they are 5 minutes apart usually. you can try to stick it out a little longer but don't wait too long especially if you live more than 20 minutes from the hospital. I agree with above poster, call labor and delivery or your ob and see what they want you to do, Goodluck mama :)
I would wait a little longer until they are 3 minutes apart but that's because here in Boston they send you back home depending on how much you have dilated. call labor and delivery and ask them what should you do every hospital is different