Hay, yan ang Braxton Hicks contractions, super normal sa ganitong stage ng pregnancy, marami sa amin ang naka-experience nyan, pero kung ang sakit ay malakas or consistent, or may bleeding or discharge, kailangan mo talaga i-check with your OB kaagad para peace of mind mo lang. Try to relax, stay hydrated, at kung umuulit ulit talaga within an hour or mas masakit, don't hesitate to contact your doctor na, better safe than sorry, lalo na sa pregnancy!