You can keep fresh breast milk at room temp for up to 6 hours, In the fridge for up to 48 hours, and in the freezer for 3 months. Never keep milk in the door of the fridge. If you can only express small amounts at a time you can add it all together as long as you cool it first and date it from the first expressed. Never add fresh milk to frozen or frozen then thawed. Be prepared to have a few attempts at getting your baby to take the bottle the first time and its best if your partner or someone else feeds as baby will smell milk from you and want to nurse instead.You can but cups from avent that are suitable for freezing and for the microwave and once you take the lid off you can put teat on use straight from the cup. Good luck hope this helps. x x