Is this normal in early pregnancy, If I even am Pregnant? So confused;?

I had unprotected sex about 3 weeks ago, And about a week later I took a pregnancy test and it had a blue line, and another noticeable but very faint blue line. Last week, I had light brown discharge, that turned to like a pinkish brown the next day, only lasted for 2 days and not enough to wear a pad or anything, I read that it could of been implantation bleeding? I also had spotting before I got the brown discharge, it was like specks of blood after I wiped, only once though. Now today, I noticed I have this thick white discharge, with DARK dark brown in it, almost like black clumps in my discharge, very noticeable.. I don't know what's going on with me, I've never been on any type of birth control in my life. and Usually when I have brown discharge, it ended up turning into my normal period, but this time it went away. I have headaches, and cramping a lot! please help. I think it may be pregnancy but is this stuff normal in early pregnancy?