There may be amenorrhea for several months or irregularity of periods after stopping the depo shots. If you want to try for conception, try having intercourse every month around your ovulation days as it is the best time for conceiving. Ovulation is the release of a single, mature egg from a follicle that developed in the ovary. It usually occurs regularly, around day 14 of a 28-day menstrual cycle. The best timing of intercourse in order to conceive is day 10, 12, 14 and 16 (in case of late ovulation) of a 28 day cycle. After intercourse, do not wash immediately and keep on lying for some time. You can also keep a pillow under your buttocks so that semen does not come out. Have plenty of foreplay or use water based lubricants during intercourse.
Drugs like Clomiphene can be used for helping in conception. Consult a gynecologist and get it prescribed.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.