Breast milk: pumping & storing

My daughter is 5 days old and my milk started coming in really well so I started pumping a few times a day so that her dad can feed her when he gets off work. I've been pumping 1-2 oz at a time and leaving it in bottles in the fridge for him to warm under running water. If I'm only pumping 1-2 oz a few times a day could I add the milk I pump to the same bottle in the fridge if it's all going to be used in less than 12 hrs?