The effects of depo Provera can last for up to 18 months. So, it is entirely possible that you are still having after effects. If you were my patient, I would probably begin a work up for infertility though, starting with ovulation predictors. If you ARE ovulating, we would continue looking for other problems such as blocked tubes or low sperm count.
My best advice stay off birth control , get healthy take iron pills start taking prenatal pills . Go see a dr for a check up to make sure everything is ok , goodluck & I hope you have a blessing from above .