Judging from what I've seen and heard it doesn't seem like premies stay in hosp more than 2 weeks these days, and that seems to be on the long end. I mostly hear a week or so.
You are doing really good and sound determined. Just stay calm and know that doing that is best for not only you, but the babies too. Your o2 is about what it would normally be for any 'healthy' mom carrying twins. Mine went down to 94 hon-and I only had one in there! I was all worried but the docs said its normal for it to go down.
As cfers being preg, I think we have a tendency to look at every single thing thats not usual for us, (bc we are so in tune with our bodies,) and assume that this is a warning sign, or that is a warning sign...when most symptoms preg cfers get-are the same symptoms non cf preggers get.
I was out of breath, short of breath, coughing more...and often worried that my cf was acting up, or maybe I would go early bc I was short of breath, when most docs reminded me that I was feeling the same symptoms that occur in 'normal' pregnancies.