I think that there are two layers to the opening. Sometimes it feels like it's dialated a little but really the inner layer is still closed? Dunno. Anyway, I checked today, too, and while it was still very posterior and closed, it was more anterior than a few weeks ago and only about as thick as the rest of the uterus that I can feel.
Can anyone else feel the baby's head? Mine is so low that I have this hard head in my vagina and that's what I press the cevix against to see if it's softer or thinner.