Feeling confused

Siobhan
Hi I found out about a month ago I am pregnant . 
Me and my partner are over the moon. 
I am 4 weeks and 2 days . 
This morning I did a clear blue digital test  straight away it came up pregnant which made me smile however it said 2-3 weeks ? 
I was expecting to get a 3+?  Has this happened to anyone else ? Thanks