Hay nako, that's definitely something you need to discuss with your OB right away po, sometimes ang gap sa biometry ay pwedeng normal variation lang, pero 5 weeks difference is significant enough na kailangan i-check ng doctor mo thoroughly, especially since you're already at 36 weeks. One of my mum friends had something similar and her doc just did extra monitoring, but really talaga you shouldn't worry alone, let your OB assess kung may underlying concern or if it's just how baby is measuring, okay?