We flew from San Francisco to Boston with DD when she was 5 weeks old. I had a terrible labor and delivery, and ended up with a separated pelvis. Travel was a challenge, mostly because of ME, not DD! Some things I remember (DD is now 21, it's been a few years…)
Take plenty of wipes and diapers. Also take 2 changes of clothes for the baby and one for yourself. I found the one-piece sleeper-suits to be best for DD. We also took her blankie, a receiving blanket, a sweater, and a hat for her- airplanes can get chilly. I will second the recommendation of compression socks for you, to help prevent blood clots in your legs. Also dress in layers, so you can bundle up/strip down to acclimate your body temp- nursing is hot work! Gotta take care of Mom!
If your airplane has rows that have 3 seats in them, reserve the window for yourself and the aisle for your DH. Unless it's a full flight, most folks won't choose/book a middle seat, which will leave you a little extra space in flight, as you'll have that spare seat. If someone is assigned that seat, I bet 99.9999% of the time, they will happily swap your DH's aisle seat for their middle seat, and you and DH can sit next to each other. (A United flight attendant recommended that if the seating is 5-across, we reserve the #2 and #4 seats- NOBODY wants that middle #3 seat!)
I second reserving the window seat for yourself. Not only is there more privacy for nursing, but you won't have to worry about someone bumping into your baby's head as s/he lies in your arms.
I nursed DD, but she also took breast milk from a bottle, and would also drink formula. It's not safe (microbiologically) to travel with milk in a bottle unless you can keep it cold, but it might be helpful to teach your baby to drink formula. When traveling, sometimes it just isn't feasible to breast feed (traveling down the highway at rush hour or when there's no safe place to stop), or you might have milk issues (stress, dehydration can effect your production) and you don't want a hungry baby. I always packed a can of dry formula (or put "enough" in a ziplock), an empty bottle, and made formula using bottled water if we needed it while traveling.
Can you ship the pack-n-play or whatever it is that you are taking with you for baby's bed? It'll make your luggage lighter. Also, many of the "baby/child care equipment" catalogs market a heavy-duty car seat carrier. We had one for DD's carseat, and in over 4 years of air travel, her carseat was NEVER damaged by the airlines (and the carrier was big enough so that when DD was potty training, we could put her potty in the "lap" of the car seat and zip them both up together. This was good for good for going to and from the airport, as she had a specific "travel" car seat, and we'd stow the potty in the carrier when using the car seat on the plane).
We always used an umbrella stroller when we traveled. Yes, I know, babies seem to "slump" in them, but they are small, lightweight, and easy to handle. This was SO much easier to deal with than the full-sized stroller, and we only really needed it for the airport.
Nurse during take off and landing. You might need a small pillow (maybe 6" by 12") for behind your back as you will need to sort-of lean forward to maintain a nursing position, but it's so much better for the baby's ears if you can keep him/her sucking to offset the pressure changes. (or use a bottle if your baby will take one)
Good luck. Hopefully your baby will arrive on schedule and your travel plans will all work out. Stay hydrated, get plenty of rest before travel (you sleep when baby sleeps, the housework and laundry will wait for you), and make sure your DH knows he'll need to manage all the carry-ons, luggage, etc., because YOU will have your hands (and arms, and heart) FULL!