Confused on why I'm 6 days late and a negative HPT

I have been trying to get pregnant this past month or so and I am now 6 days late! I have taken a few pregnancy test, but they are all saying negative. However, today I took a test and there was a very faint line, so I took the strip out to see if there was a line or not. Well, about 5-7 minutes later the line got darker! I thought, maybe the strip result changed once I took it out. But then, I took a digital test and it said "not pregnant", I'm so confused. Typically, I'm never late by 6 days, but maybe one....I'm not sure if I'm taking a HPT too soon or if I am in fact just skipping a period. The obvious answer is "go see my Dr.", but I'm just curious. I also checked my cervix, which I have never done before, and a friend of mine told me to try it. I have no clue what I'm looking for, but my middle finger did touch a hard like "lump" with a hole like indent towards the left (does that mean my cervix is low and hard?)....Not sure if any of that matters, but what are your thoughts? I also have been feeling a little more run down than usual, but I do have some medical issues that can cause this to occur and I'm a bit in the dark right now.

[Missy818]

Also, on Saturday I had intercourse twice and when I wiped I had some light blood mixed into the fluid after I wiped. Have you heard of this before?