Ovulation test help?

ho

So I have the basic idea of how ovulation test works (test line darker to show ovulation?). But what I wonder is how fast this can change.

So I took an ovulation test today and the test line was barely even visible so I am aware this means ai am not ovulating. But how fast could this line change to darker? Could I wake up tomorrow and the line be darker? Should I be testing every day?