Positive or indent lines?

I’ve taken two first response tests the past two days on DPO8 and DPO9. They both have faint lines that appeared right away. DPO9’s line is darker than DPO8s. I’ve included a picture. You really have to look to see it on DPO8, but it was definitely there. So my question is, if they’re not evap lines, how can I tell if they are indent lines? What does an indent line look like? Today’s line is pink - even if you can’t tell in the pic. I couldn’t tell if yesterday’s line was pink or not.

Isn’t an indent line is a flaw in the test? And if so, would it be common to get one right after the other, with the second being darker? Or does this indicate pregnancy. Thanks in advance 👍🏻