I'm a FTM and had my 35 week appointment yesterday. They did the GB Strep test and then afterwards, the doc asked if I wanted her to check me. I didn't really think there would be much point at 35 weeks since I haven't been having crazy amounts of BH contractions or shown any other labor signs (that I've noticed anyway), but figured what the heck. Turns out I am already 2 cms dilated and 50% effaced. I know it is possible for people to walk around for weeks at only a couple cms dilation, but just wondering what the STM+ experience has been with dilating early. How long was it before you progressed further and and then finally went into labor? I am kind of thinking that I don't want to be checked again until 38 weeks or so because my baby girl seemed to freak out afterwards since apparently her head is very far down (I guess that would explain some of the pelvic pain I've been having lately). Just kinda want to get an idea of whether there is a norm with this. Obviously every woman is different, but just figured I'd ask the voice of experience. Thanks Ladies! 
 
                
Re: Dilation and Effacement? STM+ Experience?
You already answered it. It doesn't mean anything. I was the same as you at 37W last time (the first time they checked me), and DD was 1 week overdue. I'm asking NOT to be checked this time until week 39/40 - its pretty pointless info.
I had my first check at 36 weeks when I was pregnant with DD. I was 2cm and 70% effaced. The midwife told me just to be sure that my bag was packed because she'd put money on me not going past my due date. When I went in for my 37 week appointment I was 3cm and 80% effaced. I went into labor at 37w5d.
I know that some people stay dilated for a long time, but that wasn't my situation. I have also heard that effacement is actually a better predictor of labor than dilation. I can't remember where I heard that and I don't know if it's true...
I read that first time moms usually efface before dilating and that ST+ moms usually dilate first or at the same time as effacing.
For me, I don't think I was dilated at all when active labor started even though I had been having regular BH for at least a month (timeable even). When I went in after my water broke I was only 2cm. Just 6 hours later I was fully dilated.
On the other hand, my friend was 4 cm dilated for over 2 weeks before active labor started.
I don't think it matters.
At my appointment the week before I delivered DD, I was not dilated at all. Doctor was concerned that I wouldn't go on my own........that was false! When we got to the hospital when I was in labor with DD, I was thinking that I wouldn't be very dilated but my contractions were really strong so I went anyway.......turns out I was at 4. 15 minutes later when they checked again I was at 9! I think this just proves that your body will dilate when it's ready.
I know people who walked around 2 cm dilated for 6 weeks before their child was born. I don't really think it means anything until you're actually having contractions or your water breaks.
Baby on Board - My Blog
 
 
Have you been on bedrest? I would have been concerned being dilated 4, or even 1 at 31 weeks...