How can you tell if your nipples are infected after getting them pierced?

Painful to touch, warm to the touch, discharge of greenish yellowish puss are typical signs of an infection which needs to be dealt with in a timely fashion. Discharge of clear fluid, enlarging of the piercings entry and exit points, itchy piercings are signs of an allergic reaction, this can be the metal or a combination of the metal and the cleaning solution being used to clean the piercings. Discharge of whitish fluid (not Puss) and slight discomfort lasting only momentary are signs that the piercing is healing with no ill effect.