Am I pregnant? Possible implanation...?

I am (about) 4-5 days late. I started a light spotting today. Last night it was very little pinkish and today a dark brown glob and only shows when I wipe. I am hving unprotected sex to get pregnant but did not check my ovulation so not sure when I was. I've had slight nausea, no breast soreness, fatigue but 2 negative pregnancy test (Taken around 7 days ago and again about 5 days ago)