Some basic facts about ovulation and the possibility of becoming pregnant

Some basic facts about ovulation and the possibility of becoming pregnant:
1. A woman ovulates approximately once every 28 days. Therefore the chance that a woman will ovulate on any randomly selected day is 3.57 percent.
2. When a woman ovulates, the egg is able to be fertilized for 12-24 hours (1 day).
3. When sperm enters the woman's body, it remains alive and able to fertilize an egg for 1-5 days.
4. It takes emergency contraception from 12-24 hours to be effective (1 day).
5. Emergency contraception remains effective for at least 10 days.
6. It takes a fertilized egg 5-7 days after ovulation to implant in the woman's womb.
In 78% of all cases, taking emergency contraception is unnecessary because the woman could not have conceived a child (meaning she was not fertile to begin with).
Thus, emergency contraception only has an effect 22 percent of the time.
Of those 22 percent, the mode of action in which the emergency contraception works depends on when the woman takes it:
Emergency contraception taken within 24 hours, will act 43 percent of the time by preventing implantation (thus killing the newly created child)
Emergency contraception taken between 24 and 48 hours will act 57 percent of the time by preventing implantation (thus killing the newly created child)
Emergency contraception taken between 48 and 72 hours will act 71 percent of the time by preventing implantation (thus killing the newly created child)