Elisa,
I use gloves for everything.  I have 2 small children in overcrowded NY City
public schools, and never know when they are going to bring something home.  I
would hate to pass it on to a baby, so I scrub and glove whenever handling the
baby, the breast, expressed milk, or feeding/pumping equipment.  I change
gloves after touching something in the office- door, telephone, etc.  I am far
more worried about giving something to a baby than getting something myself
from doing a breast or oral digital exam, though I let moms apply their own
lansinoh to bleeding nipples!  Just my humble opinion.
Catherine Watson Genna, IBCLC