Help... Advice???

So 9 days beforw my period i started having very light red blood on tissue then it turned into old brown bleeding lightly-barely medium now 6 dayz prior today to when period is due. Im not really discharging much brown stuff but still crampy on my lower back and abdomen could this be implantation and uterus lining getting ready for pregnancy? Took a cheap test in middle of day yesterday it was negative.