Positive test after depo

Mamasita

So I had my last depo shot in may and in august when I should have returned I decided to stop as I was puttin on weight and not feeling myself. Whilst on the depo my period stopped and even after the depo was due in august aunt flow still didn't return ... today ..a day befor I go doctors I took a home pregnancy test and here it is ....... I'm over the moon but a little confused as to how when I haven't had af visit since befor my injection in may