My last period was March 4th-10th. My period for this month was 15 days late . My periods are usually somewhat heavy and dark red when I start. This morning when I wiped I had very light pink color and it was very light blood. I took a test a few weeks ago and it said negative, but I know sometimes they wont show positive until you're so far along. So what I'm wondering is could this be a weird period due to it being so late, or could it possibly be implantation bleeding?