The same thing happened to my daughter she had 1 period and not till a year later she had another then she was normal. But tell your parents so they can look out for anything else that may go on
Tell your parent for sure, but I was like that. My period wouldn't come for 3/4 months during the first year and a Half
You should tell your gaurdian, don't be embarrassed, its not uncommon for things like that to occur, but then again it isn't that normal, there could be something going on, but doesn't sound serious...good luck
BTW I am not sexually aactive