Update

Everything went wonderfully at my specialist appointment! Well, except for the 10 or 11 vials of blood that they drew. About four years ago that would have sent me into orbit; it's amazing what having two kids will do for your ability to deal with needles. :-) I really like the specialist; I wasn't sure when I first saw her picture on the internet (yes, I was judging by her looks...ha). She is pretty sure we're having a girl, although I can't seem to commit to that until I hear my regular doc give his opinion. :-)
She was impressed with my cervical length, which said was about 5 cm. That is the distance from the bag of water to the outside of my cervix, and 5 cm. is a very good length. From what I have read, 3.4-4.0 cm. is an average cervix length. She also said my cervix is still curved and said that we would see the cervix straighten out before it starts shortening. All of that to say that we are at a very good starting point! She doesn't seem to think I have classic incompetent cervix (which I had wondered from the beginning), and that's why she ordered all the bloodwork to check for other issues that could have caused my cervix to open prematurely last time. She also said that she won't even consider a stitch unless I go under 2 cm. before 24 weeks.
So, that is what we're working with! I was extremely relieved to hear how long my cervix is and to hear that a cervix that is shortening rarely loses more than 1 cm. in two weeks. I guess all my weird sensations I can actually chalk up to a "normal" pregnancy! :-)
Gotta run!