http://www.imaginis.com/breasthealth/benign.asp
<there's a whole section there on nipple discharge >

Up to 20% of women may experience spontaneous milky, opalescent, or clear
fluid nipple discharge. During breast self-exam, fluid may normally be
expressed from the breasts of 50% to 60% of Caucasian (White) and
African-American women and 40% of Asian-American women. Usually, a discharge
that is clear, milky, yellow, or green, and is noted from both nipples, is
not associated with breast cancer.

Women should report persistent nipple discharge to their doctors for
analysis. To examine nipple discharge, a small amount of the fluid is placed
on glass slides under a microscope to determine if cancer cells are present.

that would be put your mind at ease
J