Thanks for all the responses. I really appreciate you guys taking the time. I know everything looks good right now. I just am starting to worry because there is an obvious change and we are approaching the time when I started to have issues. Fortunately I usually have Non painful contractions with changes in cervix and I haven't yet. I hope yesterdays change is not indicative of issues to come. I guess my sono next week will tell me.
I freaked out looking at my numbers the first few weeks (5 prior to 15 weeks, then 4.7, 4.2, and 3.6). I was not okay with the slope of that line. But then the next week it was >4, then down to 3.7 at my a/s. Today it was 4.2. I think the initial shortening was normal and just what happens when the baby has some actual weight. And now it fluctuates within a certain range.
I also really think the 17p shots are helping me. We'll never know exactly what happened last time, but I went from having a normal cervical length at 18 weeks (3.6) to being in preterm labor 2 weeks later with an infection. Whether my cervix is holding up this time because it just isn't an issue (and wasn't last time) or because the shots are helping is just something I don't think we'll ever know.