Pregnancies are often accompanied by changes in the functioning of a woman's body. Early pregnancy symptoms can sometimes happen before a missed period and before a positive pregnancy test and are usually related to the pregnancy hormone hCG or "Human Chorionic Gonadotropin." These physical symptoms affect all major body systems and can include pelvic pain, missed periods, nausea, vomiting, heartburn, abdominal aches, hemorrhoids, and shortness of breath. Many of them exist to such a degree that they are both unpleasant and have potentially negative effects on a woman's life.