No period yet!

Isabella
So my last period was February 3rd. On the 20th and 21st  about three times a day when I would pee when I wiped there was some light pink blood, followed by some brown discharge or something. I thought maybe that could be inplantation bleeding. I took a test three days later and no positive. 
I was suppose to start my period Wednesday, I usually wake up to blood the morning of my first day and nothing. So I took a test and still negative. I took a test yesterday afternoon and still negative. 
Now I'm three days late, still no sign of my period. I'm so confused right now! 
Any adovice from anyone?