HI there. Am sorry I missed your original post, but congratulations on your twins! It is probably a bit overwhelming at the mo, but think positively, they're good weights and they got the steroid injections.
I was in a similar position - went into labour (although I didn't know it was labour - I was just having back ache) at 27+4. I had the drugs to stop the contractions, and the steroids, but I was also starting to dilate. I think that is usually the crucial factor - if you're just contracting they can usually stop them for quite a while, I was told because I'd started to dilate (even though my waters were intact), I'd go a maximum of a week. As it turned out, I went back into labour 48 hours later and went to 10cm in minutes.
But thats all by the by now, they're here! My twins were 1.078kg and 1.096kg so about 2lb 6oz each. Twin 2 needed to be ventilated for about 12 hours, Twin 1 was OK. As everyone has said, it'll be a bit of an emotional roller coaster. I think with twins its hard because one generally does better than the other to start with so although you're pleased with one's progress, you automatically compare it to the other and then worry! I know it doesn't seem like it now, but I was told at 27 weeks that they were really in hospital to feed and grow - they weren't classed as really early.
I'd encourage you to be at the hospital as much as you can, especially ward rounds so you get to know the staff and they get to know you. I just felt like I was therefore upto speed and somehow could keep some control.
Expressing - stimulate all your senses whilst you're trying to express - my twins wore little fabric goggles to start with to protect their eyes from the UV lights, sounds bizarre but I used to sniff the goggles whilst I was expressing (to get the babies' smell). They'd taken photos of them for me that I had up on my bedside cabinet, so I could see them. Warm showers and some gentle massge of your boobs before you start can help. I was also told that its the amount of food that you eat that affects your supply, not just your liquid intake, so make sure you're eating. I used to have a sandwich when I got up in the middle of the night to express. Its tricky being in a different hospital as I was able to go and see them when I took the expressed milk up to the unit. Just try to express every 3 hours day and night to get your supply going.
We were told we could expect to go home by their due date. In fact, they were in SCBU for just over 8 weeks, so they came home at the equivalent of 36+5. They had to be regulating their own body temperatures, gaining weight, and be taking their feeds, whether that was by breast or bottle. They were 4lb 9oz each when they came home.
They're 7 now, have absolutely no lasting effects of their prematurity. They were a little lighter than their peers until they were about 18 months old, but hit all their milestones other than their speech which was about 3 months behind (although I still think this was a twin thing rather than a prematurity thing). We saw a consultant (as out patients) until they were 2 and he signed us off after that.
Good luck, just take each day as it comes, try to get as much rest as you can whilst you (and they) are in hospital.
Let us know how you get on. BEst wishes, Mandy