Need some help ??

Had bloods taken as had so.e bleeding and it come back with 30,000 hcg to witch the lady said I'd I was over 6 weeks had a scan a week later and the lady said I was a bout 4 weeks ? This is where I get confused as was reading the charts and the carts on it say 6weeks+, my last period was from the 29th Jan-6 Feb so I'm very confused