Since the Depo shot is intended to be a long lasting form of birth control, it is best to plan ahead when you are looking to become pregnant. You should first talk to your doctor about how long it will take for the drug to leave your system.
It was designed to offer protection for around three months, so you will at least need to plan this amount of time before you begin trying. You should also begin tracking your ovulation cycle so that you will know when it has returned to its normal cycle.
This will also give you the information that you need to know when the best time to have intercourse is. Your doctor will also have some particular things that you can try to speed up the process of becoming pregnant as well, so make sure that you have a preconception appointment early on in the process.
It is likely that your doctor will suggest taking a prenatal vitamin as well as adding certain things to your diet and maintaining a healthy weight. By planning ahead and being a little bit patient, you should have no problem becoming pregnant after coming off of the Depo Shot.