I go through so many nursing pads. It's also the body's way to prevent engorgement and relieve that feeling of fullness nursing moms get in their breasts. Leaking is unpredictable, unfortunately.
Some moms leak only during the early weeks of breastfeeding while others leak for many months.
Oxytocin is also present during orgasm, so don't be too surprised if your milk sprays during climax. Some say leaking is a problem only until the sphincter muscle in the nipple gets in shape, and should cease soon after. How quickly or slowly this happens varies from woman to woman. You can also use the base of the palm of your hands to press over the nipple. If you are sitting at a table, cup your chin in your hands and press your forearms into your breasts.