Coming off 1st depo-provera shot. sore breasts, lower back pain, fatigue, light period. had unprotected sex with bf couple weeks ago. am i pregnant?

Possible: If your first shot was 6+ days after your last period & you had sexual relations within a week of getting the shot then, you may not be protected. Your periods will not completely disappear for at least 6-12 months so you may consider getting a pregnancy test done if you do not get your next expected period. Remember, the shot by itself as a contraceptive method fails 1-3% of the time.