Lack of menstruation is an expected side effect when coming off birth control pills. Lack of the menstruation is due to lack of ovulation. Ovulation is prevented while a woman takes birth control pills. Without ovulation, irregular periods are also possible. Women usually need a few months to establish spontaneous ovulation and to return to their pre-birth control (BC) fertilization ability.
The maximum waiting period for normal periods is 2 years. If you are in a hurry to conceive you can try ovulation stimulators. Ovulation can be stimulated with oral contraceptives or estrogen blockers (clomiphene). You can consult your gynecologist about this.