How early did you dilate?

sware2010

I was sent to L&D for contractions every 3-4 minutes last week when I was 31w0d. I was 1-2cm dilated and 50% effaced. FFN was negative. My reason for admission was stated as "preterm labor vs preterm contractions". The OB said they just couldn't know which it was without knowing whether I dilated on my own (which would make them just preterm cntractions), or the contractions actually caused the dilation (which would be preterm labor). Just curious as to how many of you have dilated and effaced at 31wks without regular contractions and how much. Thanks!

Btw, everything calmed down with lots of terb and now Niphedipine around the clock. And with the FFN being negative, I'm not too concerned. Just curious. TIA