What do you all think?

Jennifer • I`m a work in progress.
AF is due today. I had what I think was implantation bleeding 6 days ago. Just a small amount of dark brown spotting and no spotting since. How does one know the difference between evaporation lines and a true BFP? This pic was taken about 6 mins post testing. It very clear to see in person but hard to get a good pic so tweaking was necessary.