Back pain, pelvic pain and hip pain are all signs of labor, states WebMD. Aching muscles in the legs may occur due to arterial pressure from the uterus, according to Childbirth Connection. Other signs include passing of the mucus plug, water breaking and cervical dilation.
A baby's head settles into the pelvis approximately two to three weeks before labor in a process known as lightening. During this time, women may feel a relief of pressure below the diaphragm and have an urge to urinate more frequently. As the cervix begins to dilate, the mucus plug begins to pass through the vagina. The mucus may be clear or streaked with blood. Just before labor begins, women may experience extreme fatigue, a burst of energy or flu-like symptoms, according to Childbirth Connection.
When a woman starts having contractions, the abdominal muscles tighten, causing symptoms such as pelvic pressure and a dull ache in the lower back or abdomen. Some women experience false contractions known as Braxton Hicks contractions that are generally not painful, don't worsen while walking, don't occur at regular intervals and don't increase in frequency over time. Women should call a healthcare provider if they believe their water has broken, if they are bleeding or if contractions have been occurring approximately every five minutes for an hour, advises WebMD.