Storage of milk while pumping at work?

stemms8810

I am sure this has been asked before so sorry if this is redundant.

I am returning to work next week.  I have a pump and it came with a cooler bag and 4 bottles.  I will need to pump 3 times at work for sure.  How do you store the milk after you pump?  I only have 4 bottles and the cooler bag will only hold that many.  If I use new bottles each time I won't have any by the 3rd pump.  Do you put in storage bags or do something else?

And I have to use the cooler bag and won't have access to a fridge as I am on the road a lot.