Clear blue digital not lining up with how many weeks

My last period was 22nd November, that would make me 6 weeks correct?

When I put in the baby due date indicator it also says 6 weeks but I just took a clear blue digital and it says conception was 2-3 weeks ago (which seems to line up with conception, not that I was tracking) but according to the pamphlet 2-3wks (conception) indicates I am 4-5 weeks pregnant ?