Hindi ako personally nakaexperience nito, pero alam ko na ang Depo can really mess with your cycle talaga, may kaibigan akong nag-miss ng shot at tumatak siya ng mahabang time bago bumalik ang period niya, so hindi lang pregnancy ang possible reason. Best talaga na magcheck ka with your OB to see if you're pregnant or kung ano na ang nangyari sa hormones mo from missing the shot, kasi mas malinaw ang picture with a test or ultrasound, don't stress too much in the meantime, pero don't self-diagnose din.