Is it normal?

I'm completely new to all of this we just recently (2 weeks ago) decided to start trying the last day of my period was Saturday so I went to target and got their brand of the ovulation testing strips I have tested once every day since then when I wake up and there is always a second line that's close to the color of the test line but not the same or darker than it. Just wondering if that is normal I was under the impression if it was negative there wouldn't be a second line at all