Evaporation Line?

Yesterday I was 5days post my frozen embryo transfer. When I did a transfer 5 years ago I was able to get a positive pregnancy test on the 5th day. I took an FRER about 1am and it was negative. Then took another FRER at about 5:30am. It was negative as well. I was just so anxious to test. I took this Walmart cheapie test in the evening at about 8pm and at first it was negative. I stayed around a few minutes to see the results but it looked like there was no line. Then today I pull out the test i took last night and it has a slight pink line. Think it's just an evap line? I have read a lot of reviews on this test with it being inaccurate and causing a lot of negatives when people are indeed pregnant. People on the reviews have said it barely ever shows much of a line. To come back to mine and see the slight pink made me hopeful. Think it's just false hope since it was hours later I saw this?