HPT test question! (Pic)

So I took an hpt test Tuesday evening and it was a BFN. Then as I went to throw it away this morning I see a faint line there! It's so hard to get a pic of it bc of glare but I def see something. Period would be 4 days late today. Or due to it being several days later just assume it's null and void? Could it be an Evap line? I don't know what those look like, anyone have a pic of one? Thinking I should just test again tomorrow morning but just curious what you ladiesthink?