Symptoms

• According to the American Pregnancy Association (APA), missed periods are the most common symptom that signifies a woman might be pregnant. Other symptoms that may arise before you even miss your first period are swelling or tenderness of the breasts, fatigue, and nausea or vomiting, particularly in the morning. Some other early symptoms are lower back aches, darkening of the areolae, food cravings and more frequent urination. If you believe you are showing signs of pregnancy, purchase a home pregnancy test or visit your doctor..
  
  

First Trimester

• According to the University of Virginia Health System, during the first three months of pregnancy, the woman's body will change more on the inside than on the outside. The uterus begins to grow, hormonal activity increases, and cardiac volume increases. Inside the uterus, the embryo is implanted and transforms from a lump of cells to a fully formed (though small) fetus with all the major body organs and systems already formed.
  
  

Second Trimester

• The woman's body continues to change and begins to show visible signs of pregnancy. Initial symptoms such as fatigue, breast tenderness and nausea may begin to subside during the second trimester, but it's not uncommon for them to remain throughout pregnancy. The mother-to-be may experience an increase in appetite and find changes in her skin or gums due to hormonal changes. The fetus continues to grow and form, begins to move, reacts to stimuli, and develops the reflexes necessary for survival: sucking and swallowing.
  
  

Third Trimester

• The mother will likely gain the bulk of her weight during the third trimester. Irregular Braxton-Hicks contractions may begin as the uterus prepares for delivery. Due to the increasing size of the baby, the mother may begin to develop constipation, more frequent urination, indigestion and backaches. The fetus continues to gain weight, and organs continue to mature. The fetus also begins to take on the appearance and abilities of a baby. It can see, hear, cry and suck her or his thumb.
  
  

Complications

• Most pregnant women deliver healthy babies, but even in the healthiest women, every pregnancy carries a certain amount of risks. According to the Baby Center Medical Advisory Board, there are some signs that pregnant women should never ignore, such as vaginal bleeding or spotting, fever over 100 degrees Fahrenheit, abdominal pain or cramping, excessive pelvic pressure or back pain, painful urination, lack of urination, excessive constipation or diarrhea, excessive or sudden swelling, disturbances in the vision, fainting, chest pain, or intense, persistent itching. Always call your health care provider to discuss any unusual or persistent symptoms.