I am pregnant (5 weeks, 1st pregnancy) and had been experiencing what I assume to be implantation bleeding about a week ago (small amount of brownish discharge). It has stopped but I am now having dark gray discharge. There is no odor, no discomfort "down there", everything is fine except for this alarming color. I am at a loss for what this could be, but am positive it isn't some sort of STI. Is this normal?