my last due depo injection was dec 5 2007 but i did not get it however i had unprotected sex the morning before my next injection was due what are the chances of the sperm living long enough for when the depo starts to wear off after the 5th, also for the past week i have been feeling nausea, having headaches, sore breasts, frequent urination, lower back pains could these be side effects of the depo wearing off or am i pregnant, i don't think i am pregnant because while on depo which i was on for a year i would bleed continually off on on after about 6-8 weeks after recieving the shot. when i stop the shot i was spotting light red blood off and on and now the blood looks brownish then a little red maybe a blood clot, bleeding would then cease and then the brown discharge again. is it possible that i could be pregnant or this is depo way of leaving the body. oh i forgot to mention that the injection that was due dec 5 would have made 14 weeks from the last shot because one of two of the months had 5 wks and my dr counted months and not weeks so my next injection was due on my grace period. i took a pg test on friday of last week it was negative but i am still having these pregnancy feelings