To know whether a pain is serious or not it is essential to know nature of pain. If it is intermittent, regular pain with increasing intensity associated with tightening of the stomach the pain may be due to preterm labour. However, non-specific pain around 8 months may be due to Braxton Hicks contractions or false labor. Unilateral pain could be due to mechanical strain or intraabdominal pathology.
Please rate your pain in a scale of 1 to 10 and review with your Obstetrician for clinical examination.