I agree with JoyRenee. I am just at 34 weeks and 2 cm dilated and 75% effaced. I was the same way wtih my daughter and held out for 38 weeks (started at 28 wks). I'm crampy and have contractions too (now on meds for it along with strict bedrest). When they're regular and the closer apart the contractions are and more intense, you'll be ready to, and trust me... the contractions just before birth will definitely let you know your little one is about to make it's debut. lol. Good luck! Try laying low for now and staying off your feet :)
No, they can only guess. It's very innaccurate. Not to mention your contractions are irregular and not intense. I was 3cm and 100% effaced for weeks before giving birth.