Dilated but Dr didn't say anything about being efaced

I'm 2 centimeters dilated but my obgyn didn't say anything about being efaced and every one is telling me that it doesn't really matter how dilated I am it's how efaced I am I'm only 33 weeks pregnant but baby measures 3 weeks ahead and so does my stomach and I'm already on weekly checks bc I was carrying twins and I still have two sacs but only one baby but that still puts me at risk premature labor and 1 week ago I wasn't dilated at all then the next week I was 2 cm