I was getting between two and three oz. per pumping session at that point. (I just looked at my little log book I kept track in.) We had to supplement with formula for a couple of weeks, but not a ton because the babies weren't eating all that much at that point. But if you keep up the pumping religiously, and then add in nursing if you want to do that, your supply is going to go up. Mine is much, much better now. I produce about 10-12 oz. in the morning and several oz. at each feeding/pumping session throughout the day. It took a few weeks to get it going, but once it got going, it was enough for two. I actually have quite a freezer stash going now, which surprises me because I thought I was going to be forever doomed to have a low supply.
Re: milk supply ?
Everyone is so different that is a hard question to answer.
For me I was getting about 6 ounces every three hours.
There are medicines/oatmeal that can help you increase your supply. www.kellymom.com has some great information.