Depo shot

When I was younger like 17 or 18 I had the depo shot and I got off it because I spotted the whole time and still had periods. Later on in my 20's I got on the pill still had periods nothing changed.recently I just got depo again and af lasted for like 2 weeks and it n vet came again I was supposed to start af in the beginning of the month but nothing had this happened to anyone else?