Hi,can't predict when the labor pain starts.Can wait till 40 weeks of pregnancy and can start induction of labour(medication to start labour pain)Doctor can predict sometimes depends on the cervical findinds after internal examination. Keep a watch on the baby movements.Admit if there is decreased fetal movements, water leak , bleeding from vagina, labour pain/any discomform.Labour pain starts in the abdomen, radiates to back and thigh, pain is intermittent with hardening of stomach, increases in duration,frequency and severity as the time progresses.