Urgent!!! IMPLANTATION BLEEDING OR LIGHT PERIOD?

Does implantation bleeding have only pink color? Or also bright red as normal? Because today, I have experienced very light period. DARK BROWN- a lot, but came very slowly. And then pink. Again brown. And red. It comes out very very slowly. That's really weird for me, my periods were always heavy and very painful. I have cramps as usual but i'm fine in the rest. 
So can it be...? Even if I had heavy red when I woke up and also later? Thanks.