I've been expressing a bit of milk every day for the past couple of days, to build up a supply so I can have a drink (or two) over Christmas. I've put each day's milk in separate storage bags in the fridge, but I'm a bit unclear about actually using the milk....for instance, my baby has a big appetite and will need more milk in one feed than I've been able to express in one day, so could I combine the milk from today and tomorrow in one bottle? If so, is it only safe to combine two consecutive days' worth (as opposed to three days worth for example?) Not done this before (I've only ever given expressed milk the same day), so I'd be grateful for any advice!