Hi,
I agree with Nome, I pumped in the morning whilst lo was feeding off my "smaller" side. I knew he was more efficient at extracting the milk so I could maximise the amount pumped.
However, after my milk supply stabilised and I was no longer so engorged in the mornings, it did become harder to pump and I had to resort to finishing off with manual expressing (ie not using the pump, just "milking". And yes, my husband would often let out a deep, low mournful "Mooooooo" when I did this, most humiliating!:D). Even so, I was always pushing to get any more than about 120ml (4 oz). Keep at it though, if you can express this much every day you will have a good supply for bottle feeding requirements, provided you don't use it all the time. I tended to bf whenever possible so I did not eat into the supply, which is now being used for daytime EBM bottles at childcare.