Confused about how far along I am. Please help!

So the date of my last period was September 4th. My cycles typically last 25-26 days. I took a test on September 29th (the day before my expected period). Based on that I assumed that today I would be around 4w5d. However when I called the dr she told me that I would be 7 weeks around my first ultrasound which is on Halloween. That would mean I'm 2 weeks.

Am I 4 weeks or 2 weeks??