Confused how far along

Annalisa

So my last period started 25th feb. I got a positive test yesterday so it worked out I am 3 weeks and now 4 days today. Today I did a digital test it says pregnant 2-3 weeks. In the instructions this says it means I am 4-5 weeks along as the test is for when you conceived. I don’t see how I can be that far along having had a period! Could the test be wrong? I mean I am happy I am pregnant just confused by the dates!