So my period came early, what do I do?

I've been on birth control for a good while now, and two days ago I went to the bathroom and wiped, and there was brown stuff. That continued until today, when I started to bleed lightly. I'm not suppose to get my period for another 2 weeks. I've been getting headaches really easily, it has been hard to sleep and even harder to stay asleep, and I've been cramping kinda bad. Me and my boyfriend had sex the last time about a week ago. Anyone know whats going on? Help?