Going back to work & expressing

Thanks again. DS is on a 4hrly feeding routine at the moment, i.e 7am, 11am, 3pm then bath-routine which is feed (6pm), bath and feed (6.30pm) and bed. He stirs at around 10pm when DH shhhh's him back to sleep, wakes at midnight or later when I feed him, then wakes again at 5am for another feed and up for the day at 7am. I plan on feeding him at 7am, express at 10am and again at 1pm and then be home in time for a 3.30/4pm feed (mum would only give him a little bit at 3pm to hold him over until I get home). So you suggest I express at 9pm (ish) again? I have quite a bit of frozen milk in the freezer. Just after DS's birth I was expressing every day, so I have milk from mid-January, February, a little bit for March, none for April and then some for May. I really dont want to waste liquid gold hence my question ... If I express today, would it be sufficient for tomorrow's feeds and so on and so on. We can defrost frozen milk in the fridge for 'in case' mum needs to top up on whatever I expressed yesterday, right? But if I keep expressing now (prior to returning to work) on top of the frozen supply that I already have PLUS expressing every day at the office, isnt that overkill? How much I pump depends on when I pump, right? And I'm confused about that too. (DS only takes one breast per feed. When I offer him the second breast he takes it but he always spits everything back up. His weight gain in good and Cecile agrees that as long as he is gaining, is happy and is obviously not hungry (which he isnt) then one breast per feed is good enough.) So, what I do is feed him, and within the following hour I express from the 'empty' breast approx 30mls in 10mins, and 50mls from the 'full' breast - also in 10mins. So that's 80mls. But I'm thinking if I express at work, after 3hrs of a feed, then I should be able (theoretically) to get at least 50mls per breast, or am I wrong? How long after a feed should I express to get optimum amount of milk? I'm aiming to brestfeed for as long as possible so I need to get it right. TIA

thank you ladies x

I'm going back to work soon (family's coming over to look after DS). I'll express so that they can give him 2 bottles during the day. DS is 4.5 months old. 1) How much would I need per feed (mls)? Obviously being breastfed I dont know how much he drinks. Is there a formula of calculating an estimate of how many mls per feed he would need? 2) I would feed him at 7am then express at 10am and again at 1pm then be home in time for his 4pm feed. Am I correct to assume that the 10am expressed milk will cover the next day's 10am feed (and the same with the 1pm feed)? Or do I have to have more milk than what I've expressed the day before? I have a supply in the freezer but I'm not expressing at the moment. I'll start expressing again this week to add thereto. I'm a bit confused as to whether what I express today will be sufficient for tomorrow's feeds.