Hay, alam ko yan na feeling kasi pati ako at few of my mum friends nag-experience ng ganyan towards the end ng pregnancy, those on-and-off pains na parang contraction pero hindi consistent pa. Since you're already 38 weeks and the pain keeps coming and going, mas better talaga na i-check mo agad with your OB para ma-confirm kung Braxton Hicks lang yan or kung may something else na nangyayari, lalo na important since you're so close na sa due date. Basta huwag mag-alala, usually normal lang yan pero important ma-monitor by your doctor para sure ka na everything's okay with baby!