I have been on my period for two weeks now and the blood is brown! I am so confused because at times it would be just spotting and other times it is heavy... what does it mean?

It is actually more common than you might think. The uterus is shedding the lining and it could possibly be that you had lining that was not shed during your last period.
If this is the very absolute first time you've had an irregular period, and you've been menstruating for at least 2 years REGULARLY in the past, I would recommend a gyn appointment to see if there's been anything funky going on with all of the hormonal changes that are happening. If anything you could get exact answers to specific questions and feel more comfortable in a body that's turned into an alien since puberty.
Good luck sweety and let us know how things turn out!