Dates mixed up- late ovulation?

Becky
Hey ladies, 
So I had a early scan last week due to some spotting, when I went I thought i was around 7 weeks and a few days, to be told I'm measuring between 5-6 weeks? I go back next week for another scan so hoping to see bambino has grown, and behaving! 
Has anyone had this and what was the outcome? 
I could have ovulated late I guess, but it confuses me trying to understand it! 🙈 
All spotting has stopped now I must add! So that's good right? ❤️