Clear blue tests?

Got my BFP on Sunday with the first response at 10 DPO.

I took the clear blue line and digital test this morning at 13 DPO. They are obviously positive.. but I was just wondering why the line clear blue test wasn’t darker?

I just assumed it would be darker since my first response tests have gotten darker every day.

First pregnancy so I’m not sure how this works 😂🥴