I started having very light brown discharge about a week before my period was due. It lasted about 3 days and it wasn't enough for a pad or tampon but I put in a pantyliner to avoid it getting on my underwear. It wasn't a light brown, it was more of a very dark, scanty brown. There was no odor, or irritation, or itching. I had no cramps, no abdominal pains, no nothing. I was thinking that maybe my period was just going to make an early arrival but instead of the spotting getting heavier and turning into a red flow, the spotting got lighter and then stopped completely after about 3 days. It's been 4 days since the spotting has stopped and my period still hasn't come. I am due today and I am having none of the PMS symptoms that I normally have, nor did I have any pms symptoms when the brown spotting occured. The only kind of pains I am having now are sharp pains on my right and left side of my belly button and it is kind of painful and I am wondering if these pains relate to the brown spotting that I might have had earlier last week. I am not on BC but I am sexually active. I am clear of all STD's as well. Same with my husband. Other than pregnancy, what could cause this? I already know that pregnancy could be a possibility but I have taken a test and it was negative.