First time mom. Pahelp po

Hello mga mamsh ask ko lang kung ano dapat sundin ko nung first ultrasound ko kasi October 20 due date ko then nung pangalawang ultrasound last sept 21 naging October 29 due date ko, hindi kopo kasi alam lmp ko hindi ko tanda. Pahelp naman po pls. Thank youu #1stimemom #advicepls