http://www.medhelp.org/posts/
Birth-
Control-Contraception-/Infertility-issues/show/1779674
I can't stand in for your doctor's advice, but since you have been sooo irregular, your body may just need more time to "reboot". Since its no longer being supplied with horomones that tell your body what to do, it has to update how it produces them for itself.
Another possibility is something developed which is unrelated to the pill. A cyst, for example, or endometriosis.