Given the data you provided (not ovulating after quitting birth control pills, having menstrual periods), you might be experiencing anovulatory menstrual cycles because your body has not returned to its own hormone production pattern. It might take several months, (sometimes even six), for the menstrual cycle to completely return to normal. Until then, all variations of the menstrual cycle and menstrual period are possible: short or long menstrual cycles, heavy or light bleeding or no bleeding at all for a period, missing ovulation, bad cramps etc.
You might just want to wait and see for a little longer. If no ovulation occurs, you might want to visit your gynecologist and consult with him. you might need medications that would stimulate ovulations. These medications are highly likely to contain hormones in order to induce the normal menstrual cycle.