Storing breast milk

I am doing strictly breastfeeding and I was recommended by my midwives to avoid pumping until it is needed like when I go back to work or if I'm going to be out of the house and leave the baby with my husband. That way the baby can continue to eat from the breast and my breast can continue to produce more milk. With that being said I used the haka when I am breastfeeding to kind of catch whatever milk leaks out of the other breast my son is only 2 weeks old so when I do use the haka to catch whatever is leaking out of the opposite breast that he's eating from it's only a little bit it's about less than an ounce in total I'm just curious if when I store the milk into the storage bags if I can add on to the milk from later feedings from the same day or if I need to put whatever milk I do collect in separate bags each time I breastfeed?