Well, I've had 5 doctor appointments since the delivery, 2 with a perinatologist and 3 with my OB. They are disagreeing slightly about what happened, but the general conclusion is that I had a partial placental abruption with Alexis, which is why I was bleeding so much. A placental abruption means that the placenta started to tear away from the wall of uterus, causing bleeding. This bleeding caused irritation, which gave me some early contractions. I also then went from not dilated at all to dilated within just a few days, with no other contractions, hence the diagnosis of incompetent cervix. They don't know what caused the abruption, especially since I was really taking it easy, but there is a higher risk with twins. I am also told that the chances of it happening again are about 15%. Great. If it does happen, there is also really nothing you can do about it.
My peri isn't quite sure if I have IC and doesn't want to rush into a cerclage, but instead wants to monitor me once a week, starting at 14 weeks. The problem is, if I truly do have IC and don't get the cerclage, even monitoring once a week could be not enough. My OB is convinced I have IC and does not want to take any chances, so I will be getting a cerclage next time and will then be on bedrest starting at 14 weeks. I feel much better about this, because I have to do everything that I possibly can do to bring home a baby.