Is It Possible To Get Pregnant Inspite Of Being On Depo Shots?

Hi okay so i started my first depo shot in November.. I bleed on and off in november and the whole december.. I was scheduled for my next shot in January me and my bf had unprotected sex he ejaculated in me 3 times 3days later i have pink discharge and what feels like vigina cramps n lower stomach pain could i be pregnant & how to get pregnant faster after depo