Hello J.,
When I had my son, I had to go back to work for about 6 weeks after my maternity leave. I was a teacher and only had a few weeks left of school. The following are the tips I have...
1. Make sure that your child is actually drinking all the milk they are giving him. My babysitter was wonderful and suggested that I start freezing my milk in icecube trays, as my son wasn't actually finishing all the milk in a bottle at one time and she was having to dispose of some of it. That is aweful when you are deserately trying to save enough milk for your child. Each ice cube is 1 ounce of milk, so they can warm only a few at a time and actually determine what it is your son needs. Hopefully that will help.
2. Are you taking a picture of your child with you when you are pumping. Having a photo of your child when you are pumping will greatly increase the amount of milk you get. As well as making sure you put your feet up and play some relaxing music, possibly your favorite lullaby cd.
3. Finally, I made sure that I pumped as often as possible on the weekends as well. Often even after you have feed your son, you will have some milk that can be pumped and this will greatly increase your milk flow.
Keep in mind that once you increase your flow, you will NEED to pump when it is time, so don't delay or you will have some leakage issues.
I have many more ideas if these don't help, but I have a felling they will. My son was born 10lb. 12 oz., so as you can guess, I needed to have plenty of milk on hand for him and he actually breast fed for a few years. We were very successful with a little help from friends.
Again, I hope these ideas are helpful for you and if you need more ideas, just let me know.
Oh, and finally, it will take a couple of days for anything to take hold, so please give it time and don't give up. Your baby will love you for it.
A.