Ang ultrasound dating ay super accurate talaga lalo na sa first trimester, pero since pareho ng dates sa both scans mo (July at September), that's really reassuring na consistent ang growth ng baby mo! October 6 should be pretty reliable na, pero honestly syempre lang may slight variation pa rin kasi every baby is different, some come a few days earlier or later pa rin, so best to check with your OB din just to be sure, especially since malapit na talaga due date mo.