Positive/faint line/evap?

Niema

So I am 13dpo today. I had sex on my ovulation day, which was the 7th. I decided to take a test today. I came home, sat on the toilet and took the test. I watched it for about a minute and I didn't see a line pop up right away. My phone rung, so I sat my test down, came back about 15-20 mins later. This is what I saw.... it's super light pink, to the point I think my eyes are playing tricks on me. I don't really trust Walmart tests either.