Weird spotting, still virgin, having discomfort in abdomen around belly button

So, let's get this out of the way: I'm a virgin and I've never had any genital contact with a man, not now, not soon... But my last period acted kind of strange, I'm quite regular with a 27 day cycle, but on the 27 I started to get some very mild cramps, I usually have very painful ones for some hours and then I bleed, since I wanted to get my period that day, I masturbated in the morning (I heard it helps) no fingering though, just rubbing, I took a nap after that when I woke up, I saw a spot on my panties and thought my period would come... But, no... Just that, the next day, NOTHING, I freaked out, and started to apply heat, do yoga, drink tea, and even heard binaural beats for menses... The day after that, In the morning I had brown spotting, a few hours later I started bleeding like I normally do, I felt quite relieved, it lasted a day less than normal and it was a bit, just a bit lighter than usual, but in the last day I was just spotting brown, I had to use a pad... And that freaked me out making me think it was implantation blood...

I also have discomfort in my abdomen around my bellybutton, sometimes up, mostly down, my breast get a bit tender every now and then, nothing painful (my mom told me its because they are growing), also, I noticed a line from my bellybutton down, its a bit dark, and it freaked me out as well since its found in many pregnant woman (or over weight, but I'm 54 kilos...) and on my tenth/ninth day I found some very, very small... Blood? "Pieces" when I wiped, it was like in my discharge, it was less than half a drop, and on the tenth, another drop on my panties (not sure if its the same from before though, same panties).

So please help, as I said before, I never had sex, yet I'm creeping out thinking I might be pregnant! If it helps, I'm 16 and somewhat prone to Anemia....

Thanks a lot in advance