The number of pills in each dose depends on the levels of hormones in the brand of pills being used. The most common dose is two pills. If they all used EC correctly, only 2 would become pregnant. The most common side effect of EC is nausea. Some women may experience breast tenderness.
Clinicians recommend using over-thecounter medication for motion sickness to prevent nausea.
EC is safe for almost all women. Even women who have been told they cannot take birth control pills on a regular basis because of a medical problem can generally use EC safely. It may not be a good idea for a woman to take EC during an acute migraine headache with neurologic complications. The only reason that a woman absolutely cannot use EC is if she already has an established pregnancy, because the EC will not work. EC is available only by prescription.