How long does it take for you to clear from depo?? I got my 1 and only shit that lasted 3 months Dec 6- Mar 6. Got my period instantly. March 16 to be exact! I know it takes about 4 months to get depo fully out of your system. August I really started trying to get pregnant. But still nothing. I have been doing everything possible. This is around the same time frame I got pregnant with my first, it took me about 6 months to get pregnant.