J.A.
I would question whether you're going to be able to take a sufficient amount of breastmilk on the plane with you. I have heard from moms that when they go through airport security, they have had to take sips out of bottles (breastmilk or formula), so if you're packing bottles, be prepared for that.
We flew with our twin daughters when they were 18 months old; airlines don't require children have separate seats until they are 2 years old, so it was economical for the four of us to fly on only two tickets. We ended up on a flight with empty seats, which was an unexpected blessing. I nurse the girls during take off and landing in order to help them with the pressure change.
If you and your husband are sitting together, I'm sure your husband can shield you from view while you nurse your son. if you have a sling of some sort, that can also provide extra privacy for you as well as making it easier to tote your son through the airport without worrying about a stroller. Most people are also pretty understanding of nursing moms, and you might ask if you and your husband can have the window seat. I think most people would rather swap seats and have a nursing mom sitting next to them than a screaming infant.
Good luck!