Some people confuse EC with RU-486, or mifeprex, which is known as the abortion pill. There are many ways to administer an abortion and RU-486 is one form. It is an orally taken pill that triggers a woman's period, forcing the fertilized egg out of her body. RU-486 has no connection to emergency contraception.
EC cannot terminate a pregnancy, only prevent one, so if a woman is already pregnant, it will have no effect on her. Also, taking EC will have no lasting effect that may complicate future (and wanted) pregnancies.