Uy, totally normal yan mama! Ang EDD ay maaaring mag-shift pa lalo na from first to second ultrasound kasi mas accurate ang later scans, pero ang difference mo na 6 days lang is really within the normal range talaga, basta consistent ang growth ng baby mo sa scans, you're good! A few of us moms in my circle din nag-experience ng ganitong slight changes sa due dates throughout pregnancy, so don't stress yourself, pero kung may concerns ka pa rin just mention it sa OB mo sa next check-up para peace of mind.
parang overdue naman na kapag po kase lmp ko talagang yun ang sure