Hi, Welcome to Health care magic forum.
After stopping the depo shot you should have at least one month to get pregnant. Of course it may not be the exact caliculation, but it is better to not to have conception before that period.
Brown discharge, and the cramps may be due to the infection, so i advise you to consult your doctor for treatment.
Take more of green leafy vegetables, pulses, sprouts,and
protein rich foods to have good health and blood for pregnancy
Wishing for a quick and complete recovery. Thank you.