Signs and symptoms of preterm labor include: 
Regular or frequent sensations of abdominal tightening (contractions)
Constant low, dull backache
A sensation of pelvic or lower abdominal pressure
Mild abdominal cramps
Vaginal spotting or light bleeding
Preterm rupture of membranes — in a gush or a continuous trickle of fluid after the membrane around the baby breaks or tears
A change in type of vaginal discharge — watery, mucus-like or bloody
