The symptoms of preterm labor can include:

• Regular, menstrual-like cramps, with or without diarrhea.
• A feeling of pressure in your pelvis or lower abdomen.
• A persistent, dull ache in your lower back, pelvic area, lower abdomen, or thighs.
• Changes in your vaginal discharge, which may increase in amount or become pink or reddish.
• Regular contractions for an hour. This means about 4 or more in 20 minutes, or about 8 or more within 1 hour, even after you have had a glass of water and are resting.
• Not feeling well, including:
  • Unexplained fever.
  • Fatigue.
  • Uterine tenderness.
• Vaginal bleeding.