When to pump?

mookie2110

Even though I'm a second time mom who also breastfed my first son, I have sort of forgotten all the ins and outs of nursing and when to pump etc!

My 5 day old sometimes eats from both breasts during a feeding and sometimes only from one (mostly because I cannot keep him awake for both breasts sometimes). When he eats from only one breast, should I pump the other and start a freezer stash? I don't want to create an oversupply but I also am afraid about not having enough of a supply (I had major supply issues with my first son and now I am paranoid about not having the same issues this time).  

Guess I'm just confused overall about when to pump and when not to.... I know that I should obviously pump when I miss a feeding, but when else?