confused due date

Hi, saya ni first day of last period 22 April 2022 so due date should be 27 Jan 2023 tapi bila scan baby Doctor bgtahu due date 4 Feb 2023 , tak sama dgn tarikh first day of last period. saya confused la. korang ada alami perkara yg sama? so nk ikut due date yg mana ni? 😅