Hi,
Welcome to ehealthforum,
It can take some time for your normal fertility to come back (depending on type and duration of birth control used). Chances of successful pregnancy depend on many factors (ovarian, uterine, hormonal, stress etc). You should consider getting a complete infertility work-up done for you and your partner to see if there are any underlying causes for the infertility/inability to conceive. Hormonal issues, problems involving ovaries and ovulation, uterine problems, cervical or vaginal infections should be ruled out for you (which could be affecting your period pattern). For your partner, semen analysis should be done to rule out infections and to confirm the quality and quantity of sperms produced. Treatment as needed (based on examination and investigations results) would be started to help you get pregnant. Combine checking cervical mucus changes and the BBT (basal body temperature) charting to predict your ovulation and time your intercourse for having fruitful results. Consider visiting your gynecologist/obstetrician for further evaluation and assistance.
Take care.