Doctor said I'm 5.2 weeks but idk?

This is a silly question to ask but my last period started November 6th. So by my calculations I would only be 4 weeks and 6 days but my doctor said 5.2 weeks. And no he didn't do an ultrasound beforehand or a blood test for a clue as to hcg levels. I didn't wanna seem rude telling him he might be wrong. He brought out a little wheel thing out of his pocket and then said 5.2 weeks but my due date August 13 is still the same? I'm just confused but too scared to ask lol