Mama, please check with your OB right away, especially if the tightening is painful or keeps happening regularly, okay? Better safe than sorry sa ganitong stage ng pregnancy. Pero from what a few of my mum friends shared, some cramping and tightening sensations ay normal, lalo na by 28 weeks, pero yan talaga ay best discussed with your doctor para sure everything's okay. Wag mag-alala, alam naman nila ang gagawin. Let me know how it goes!