Just to clarify, I think you are saying that you have not had your period yet (ever). In this case, sometimes there is some darker spotting before you have your first period. While your hormones are figuring out what they are supposed to be doing, you might get some signs of a period, but not the red blood you would expect. There may be just a small amount of blood that sits in the uterus before it is expelled and turns a darker color in the meantime. If you continue to get more discharge and no vaginal bleeding, see your health care provider. Also, if you are sexually active, there are other possibilities of brownish discharge and you should see your health care provider to rule out any problems.
If you haven’t stocked up on supplies for your period yet, I suggest you get some soon because I bet you are about to start your period, if that wasn’t your first one. The blackish-brownish stuff is kind of priming the pump for your period – lame analogy, I know, but true. I usually get that before and after. Not all period blood and discharge is bright red. For a healthcare professional slant, check out Sandy’s excellent answer.
Despite stereotypical (and excruciatingly inaccurate) portrayals of what being on your period looks like, period blood doesn't actually look like regular blood, most of the time at least. A lot of the time, period blood is more like what you described as "blackish-brownish stuff", especially if it's been there for more than an hour or so. You should demand that someone you take you out to dinner because, girl, sounds like you started your period.