Can you become pregnant on the depo shot

Patient: There is very low chance of becoming pregnant while using Depo Provera when used properly. However, there is no 100% effective contraceptive methods. On top of that, it is very important to use a backup contraceptive method such as female or male condoms during the first week of Depo provera to avoid possible pregnancies while the medication starts working. Since you had sex the next day, I would suggest you to take a Home pregnancy test and if positive confirm it with a blood pregnancy test done by your health care provider.