Should my birth control shot be taken 3 or 4 months after the previous shot?

The recommended interval between each contraception injection of depoprovera is every 12 weeks. In this way, the contraceptive effect (prevention of ovulation) of depoprovera is preserved. If your menses is delayed and your last depoprovera injection was more than 12 weeks ago, then it is advisable for you to see your gynaecologist to determine if you could be pregnant.