Chrissi - I think it could be any of those things, but I'm not sure which one I'd lean most towards.
I'm in a bit of unknown land right now. I'm 8dpo. Last night I was wasn't feeling all that great, and I woke up at 3:45 am really hungry (I had to eat some crackers since I felt hungry enough to feel a bit sick) and then was wide awake for about 45 min, which is typical of me in pregnancy but not normally. I took a Wondfo strip this morning and I think my eyes are just playing tricks on me, but I saw something.
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Right at 5 min I swore I saw something, but I think I was imagining it. At exactly 10 min I did see something, but it was still extremely faint and I know those tests can't be trusted past 5 min. I tried to get a pic, but they weren't good (seemed fainter than real life). I'm guessing it was my imagination or an indent at 5 min, and maybe an eval at 10 min? It's my first month ever testing with non-digi's, so I have a bit of a learning curve. I'll just have to wait until tomorrow to test again to see.
I really suspect it's nothing, but here's some POAS "porn" in case you want to check it out. These were taken at exactly 10 min.
*EDIT*: Okay, seeing them at that size once I uploaded them, I really think it was just my eyes playing tricks on me, I don't see anything now! But looking at the same pic on my cell phone, I do see something. But probably just an evap.