I need explanation

22/11/2022🥰💙14/07/2023🪽-👶11.04.2024 🥰

So I’m 24-25 weeks today I found out I was pregnant on 10th of April that I was already 6+ they did my due date for 11th of December changed it again for 7th of December but I did some calculations and am I meant to be due in November then if I was pregnant 6weeks already so I should find out that I was pregnant in march 2weeks I just didn’t know did they mistaken my due date? Thanks for help x