Had my third dose of depo-provera and had unprotected sex and my boyfriend came a little and i took next choice on day 3. any chance i can become pregnant?

Very unlikely: The failure rate of depo-provera is only 0.3%. It would be unlikely after 9 months of reliable Depo-Provera use that you would become pregnant anyway. With the addition of an emergency contraceptive, i would think it's very unlikely. Certainly, all methods have failure rates, so nothing is guaranteed, but you've cut that likelihood down to near-nothing.