implantation bleeding???

I'm new to this so I hope I can explain everything correctly.

I was on birth control for 3 months (hoping it would help me conceive when I got off it) well after my first period off the pill I used an ovulation test kit so I know I was ovulating on 9-21-09 and my period is due the week of 10-5-09 but I started bleeding a week before that(this week) it stated out as a light flow but now it's a little heavier but nothing like a period, I've only been bleeding for 2 days and it's starting to slow down again. do you think it could be implantation bleeding or did I start my period early? I am so confused. I have also started having headaches, sore nipples and underarms, frequent bathroom visits, dizziness and cramping. Please help!

Hmm not to sure.....the pill does funny things to your body, hope some one can help!