About five days ago I started experiencing brown discharge. Most of it clumps and the rest gives off a balsamic vinegar look. It's not a lot, but it's obviously noticeable to me. I last had sex a month ago and got my period a week and a half after that, like I was supposed to. I noticed that my blood was darker than normal but was still able to fill pads and tampons. The three days leading up to the bleed I noticed that I was two hours late in taking my birth control, that I almost always take on time everyday. I don't have any unusual symptoms related to pregnancy, and although there was an odor the first three days it went away as soon as I started taking cranberry pills and increased my water intake. I'm really concerned. I don't know if it could be pregnancy, implantation bleeding, a UTI or breakthrough bleeding.