J.M.
Ugh- yes, it sounds like your body is trying to get back into sync! My son was born in September 2005 and I breastfed for a year, as well. I got my first post-partum period in July 2006 and bled for 3 months straight! It took some mega-doses of birth control to stop the bleeding and get me back to normal. I had a normal period for 5 months, then we got pregnant in April of this year. I, unfortunately, miscarried at 6 weeks and my period was thrown off again. It's just your hormones trying to balance themsleves out- I'm sorry you're having to go through this! I hope that helps...
J.