1.   The fertilized egg implants and becomes a foetus.

2.   Burke explained that sometimes the egg has already implanted, too much time has passed or the drug simply fails.

3.   Of perhaps more interest, they found that the later the egg implanted itself, the greater the chance the pregnancy would fail.

4.   That is also about the time a fertilized human egg implants on the uterine wall, West said.

5.   Planned Parenthood does not consider the pill a form of abortion since it does not work if a fertilized egg has already implanted itself in the uterus.

6.   So-called ectopic pregnancies occur when a fertilized egg implants itself outside the uterus.