HELP!!

Ashley 🇵🇷
I went to get the birth control shot on May 19th which was about 5 days before I was suppose to get my period.I still haven't gotten my period and I am 15 days late now for when I suppose to get it.I read that usually after a girl have been on the shot for about 6 months that they will stop getting there period but that was the first time I have gotten the birth control shot.So am I suppose to get my period or spotting at all?And is the reason my period is super late because of the shot?