Only one depo shot but no period

Hi ladies, I am really confused. I got the depo shot (for the first and last time) on 29th Dec. I kept taking ovulatio test and was ovulating on 11th March so clearly the effects wore off early. I still have not, however, got my period and it should've come 24th March. I am so confused as I need to start my new cycle so I can start ttc. Please help if you have hade similar experiences or any insight! Thanks xxx