A.--
First of all try not to stress...that is probably the toughest advice to take, but it will make the trip a lot more emjoyable and you're milk levels will stay up more easily. I left my DS at 7 months for a trip to Atlanta, GA from Boston for 4 days, and although I didn't have a 7 hr flight, it wound up being a 9 hour commute, so I know your pain. A couple nuggets of advice:
1) Your electric pump should have come with a battery pack. It is a little black box that holds something like 8 double AAs. I have a medela PIS (pump in style) and there was a battery pack that I used instead of the plug in adapter. This is ideal for pumping on the go. You can go into a family bathroom in the airport or just a regualr handicapped stall and pump away quickly and efficiently. If you don't have a battery pack, see if you can get one before your trip. Try the internet or your local baby supply store.
2) If you don't have a manual pump, I wouldn't go out and necessarily get one, especially if you've been pumping w/ a double electric all this time. I found the manuals to be far less effecient and pretty expensive. It was also more painful. It didn't help me because I was frustrated by the inefficiency and pain level.
3) If you're planning on trying to save your milk, ask for a fridge in your hotel room. Take your milk storage bags and a couple coldpacks, along with a small cooler. You can bag up your milk, keep it in the fridge and then transport it back in your cooler for your little one. I couldn't even handle all that pumping and throwing it down the drain! If you don't plan on trying to bring it back, then this won't be necessary, but it's worth a try.
I hope that this is helpful. Try to have a great trip, take in some sights and have a heifeweitsen for me!
R. P.