If the egg is fertilized, the corpus luteum remains intact and continues to release progesterone for the first 12 weeks of pregnancy. In these 12 weeks, the placenta develops along with the fetus ...

The egg travels down the fallopian tube, into the uterus, and attaches to the uterine lining. In an ectopic pregnancy, however, the fertilized egg implants and grows outside the main cavity of the ...

releasing eggs, which can potentially be fertilized by sperm producing female sex hormones, such as progesterone and estrogen providing an environment for a fertilized egg to develop during ...

In fact, most pregnancy loss happens before the fertilized egg implants. Defining exactly when a pregnancy begins is a hot topic in some state legislatures and U.S. courts at the moment.