baby gender at due date

My last period was January 26, 2020. So counting na due date ko is november 2, 2020. Then nagpa trans v ultrasound ako, it came out na due date ko is Nov. 12. Tapos kahapon nagpa ultrasound ako for baby gender and its a baby girl! Then due date ko daw is on Oct 14. Medyo nlilito ako kasi I was expecting a baby boy according to baby gender calendar. I am 25 years old nung nag conceive pero di ko alam kung alin po yung due date ko na possible ako manganak at sure na po ba yung baby gender ko? Salamat po. First time mom here!