Unfortunatley (as far as im aware), there is nothing that doctors can give you, the depo just has to wear off naturally.
Have you actually become pregnant whilst on depo or are you just interested? If you have i'd seek medical advice immediately.
Depending how long you were on the Depo shot it can take 6 months to a year to clear your system. You may want to start charting your fertility to make sure you are ovulating either by body...