Given the appropriate time, your body will go into labor on it's own. The modern world of medicine places a lot of subjective limits on pregnancy, and will often tell you you won't be allowed to go past 40 or 41 weeks. Personally I will never go with a doctor/midwife that won't let me go until 42. Believe in and trust your body! Your amazing body knows exactly what is best for it.
Re: Dilating 1st vs 2nd pregnancy