Confused

Racheal

So, I had an early scan today because I've had an ectopic pregnancy previously.

Based on my last period, which was 24th Feb, I should be 7 weeks 2 days. According to my scan, I'm 6 weeks today. So how have I been throwing up and had sore boobs for the past 4 weeks? That would mean from conception? Isn't that not possible? Can they get it wrong on such an early scan?

Heartbeat was strong and they had no concerns, I'm just a bit confused.