Due Date Change

Di

So originally my doctor said my due date was 10/13 based on first day of LMP (I track my periods so I knew the date). Then when ultrasound was done he changed it to 10/25. I'm 30 weeks along with mo/di girls and at last visit I was told baby A weighs 3 lbs and baby B weighs 3 lbs 2 oz. He then said I more than likely won't make it to October so to start planning on having late September babies. Does this sound right? Just makes me think my original due date is/was the correct date to begin with. So confused 🤷‍♀️