A single Regional Dressage Championship program organized by the United States Dressage Federation (USDF), and recognized by the United States Equestrian Federation, Inc. (USEF), will be held in each of the nine USDF.
If fertilization and/or implantation does not take place, the system is designed to menstruate (the monthly shedding of the uterine lining). In addition, the female reproductive system produces female sex hormones that maintain the reproductive cycle.
The Female Cycle has Three Physiologic Phases: 1. The follicular phase starts with the onset of menstrual blood flow and is of variable length. This phase is normally characterized by both low estrogen and progesterone output. 2. The ovulatory phase is 1 to 3 days long, and the human ovum (egg) is released in this phase.