Evap or positve? Help... Even though it showed up 2 hours later, this has never happened

So first pic looks negative... Second pic, i noticed it changed. It doesnt do that ever. I tested a few days ago and this happened. This time the second line is darker but it still took 2 hours after the test became invalid to show up a positive line. Why? I also had a little bleeding but had rough sex last night, not really started AF but waiting to ser if it comes. 7 days late and confused right now.