Help I’m confused!!

Amy • UK 🇬🇧 Engaged💍👫 Mumma to a toddler 👦🏼💙 Pregnant with baby #2 👶🏼❤️

So today I went to my doctor for the first time since finding out I was pregnant because I was getting some brown discharge anyway nothing to worry about apparently but when I told her I had a private scan at 6 weeks and 1 day, she then started doing maths and told me I’m currently 10 weeks & 2 days but from my scan I worked out I would be 9 weeks & 6 days? My scan was 26th August, anyone know why the doctor has changed from what the scan place said?? Just a bit baffled! Only few days difference but would like to know why🙂 thanks guys x