I understand from the directions on the box that the test line must be as dark or darker than the control line in order to be read as a positive. However I notice that even when I get a negative test the darkness of the test line varies. For instance sometimes the test line is almost as dark as the control line, sometimes its very faint, and sometimes there is none at all. I’m just curious if this correlates to how close to ovulation I am? For example, I just tested today and even though it’s negative the test line is still there and moderately dark where other days one doesn’t show up at all. I guess my question is does the darkness of the second line indicate how close I am to ovulation or should all negatives be viewed the same?