Ay alam ko yan, napaka-confusing talaga especially pag may discrepancy! Karamihan sa amin, sinusundan namin ang ultrasound dating kasi mas accurate yan, lalo na kung maaga ka mag-scan, like first trimester pa lang. Ang LMP naman ay based lang sa when your last period started, pero maraming factors na pwedeng mag-affect like irregular cycles, kaya really, ang OB mo ang best person to clarify kung which one gagamitin nila as your official EDD. A few of us actually asked our doctors ulit after mag-ultrasound kasi iba rin ang counting, so hindi ka nag-iisa dito!