Sometimes excessive bleeding occurs when a woman goes off birth control. The first time I went off the pill I bleed for two months. Just when I had decided to see a doctor, it stopped and went back to normal. It happens because your body is adjusting to being off the hormones. If your period lasts more than one month or if you feel faint or tired due to anemia, you should see a doctor. Otherwise, you could just wait it out.
Generally, it can take a couple of months for fertility to return after going off the birth control pill. In most cases, the longer you are on birth control the longer it takes for your body to get back to normal.