In order to get pregnant, your body has to release an egg, a process called ovulation. Many things factor into this. Ovulation requires a delicate balance of hormones, and it doesn’t take much for the process to be thrown off. For ovulation to occur, gonadotropin-releasing hormone must stimulate the release of follicle-stimulating hormone and luteinizing hormone. Progesterone and estrogen also play a role in preparing the uterus to receive and grow the fertilized egg.