My ultrasound showed i was a week behind.. need piece of mind

So for the first time my ultrasound was a week behind my expected due date calculated by my last period. Feb 19th was the first day of my last period and I ovulated March 6th. I even had ovulation pains. 9 days after I got my first super faint positive. My period put me at nov. 26th 2021 meaning I'm 8 weeks but today my dr measured and baby was at 7 weeks 1 day. Wondering if any women have had this issue and everything be ok? I've never had it be off more than a day or so. Never enough to change my due date.