Actually, you may not need to supplement at all. Before my triplets were born I was pumping approx 2 oz per session, so I, too, bought a lact aid. I haven't used it once, and they're four months old now. I began nursing them within an hour of their birth and have never needed to supplement. In the first two days of their lives my milk supply quadrupled.
Will you be in the hospital with them right after they are born? If so, I would say try and feed them without it at first. Talk to the lactation consultant at the hospital, too, and definitely involve the nursury staff in your plan. After a couple of days, see if they can charge a hospital grade pump to the birth mother's room and see how much you are producing. This is what I did.
Bear in mind, I am supporting three babies I didn't give birth to entirely with my own breast milk (minus once in awhile, when hubby feeds one formula in the middle of the night if I'm occupied feeding one or two of the others, but this supplementation is not necessary, just convenient!)
When you hold YOUR baby to your breast, hormones will kick in just as if you'd given birth to him or her. Also, remember that the amount you're pumping isn't necessarily indicative of the amount you're producing. A pump, no matter how good, is not the same as a baby's suckle. I have a friend who has breastfed all three of her bio children quite succesfully, and she NEVER got more than a few drops when pumping. So it's good you have the Lact Aid in case, but you may not need it.
Congratulations, and good luck! <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />
