BFP or Evaporation Line with BFN?

This is a the $.88 Walmart test. After the first minute or 2 nothing showed up. I got sidetracked and about 10 minutes after taking the test I looked over and saw this. I'm worried it could be an evap line. I got one yesterday that was even lighter than this one (you can't even see yesterday's in a picture...I thought I was imagining things...but again it was closer to 8-10 minutes). I'm going to buy another brand and test tomorrow. Just wondering if anyone else has had a similar experience?