5 weeks LMP, 6 weeks size ng GS

Hi, I'm a bit curious po. Maaga pa kasi para ma sure daw kung ilang weeks na talaga kasi GS palang ang meron dahil nga po maaga pa. So, we need to go back after two more weeks to check kung meron ng heartbeat. My question po is, based on my LMP sabi ni doctora is nasa 5weeks palang daw po. Pero sa TransV naman po, ang size daw po ng GS is 6 weeks. Bakit po magkaiba? Normal po ba? Thank you. #firstbaby #1stimemom #pregnancy #advicepls #theasianparentph