I'm confused.
This all actually started in may.

Well, in may, I had a period that was really heavy and went for 6 days, stopped for 2, and then came back heavy again for another 6 days. I went to the doctor and he put me on these pills that are supposed to jump start your period. I took those for 10 days like I was supposed to and stopped it and was supposed to get my period right after but I didn't for a week.
The next 3 months, it was extremely light. And once again this month(sept). Its usually a light pink or dark brown, but sometimes there's bright red in it.
I could get away with wearing a pad, or even nothing at all. But I put a light tampon in and everytime I change it there's hardly anything on it.
Its been like this for months now and I want to know what's going on?
Is there a chance I'm pregnant? Or are my periods just royally screwed up?

I've also been having dizzy spells and some nausea and strange appetite changes.

WHAT'S GOING ON?!