My period should have been according to the <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> calander, February 1st. I got my depo shot the same day and it still hasn't started. My period was the 8th of January last month.. I had a child in August. I haven't used protection. But can the depo shot mess it up? I also took a pregnancy test the day of my shot and it was negative and haven't had sex sense then.