I have been on the injection for a year and 3 months. I was supposed to go for my next shot on the 5th October (but I didn't go) and I got my periods on the 15th October. Does this mean I can fall pregnant anytime soon or would it take a while for my fertility to be back to normal? Please help!

It can take upwards of TWO years for the effects to completely wear off and full fertility to be restored.