EAIRLY morning question

Ok so I got off depo 4 months ago , Iv had a regular period on depo as well as when I got off nothing has changed ! Until this month my 5th month my period is 3 weeks late 😳😳 could I be pregnant or could this just be depo still messing with me??? I mean I went to the doctor first day of my missed period , doc says come back in January if your period doesn't start because once depo is out your system for months it's out nothing but stress ect. Can stop your period now ! Help has this happens to Aney of you lovely ladies?