Due date disagreement

So when I went in initially, my OB said babies due date would be Dec 18th, which was a few weeks less pregnant than I thought I was (late ovulation I guess). The following 2 ultrasounds (one at 8 weeks and one at 13 weeks) measured baby at a due date of Dec 13th. So that’s what I’ve been going off of! Well I guess my OB kept the Dec 18th date because in her eyes it’s not a significant enough amount of time to make the official change. Now I’m worried I won’t get the care I need, like weekly check ups or induction at the right time if needed, since I’m almost a week off. My mom had a very complicated pregnancy so this makes me really feel I need the correct care at the correct time. Does anyone have any thoughts? Hopefully I’m overthinking this.