Hello. I'm 15 years old and started having my period at 12. It always occurred irregularly but now it's worse.

I had my period in half of June of 2016 I still remember it because it was the last day of school. Then, the whole summer break went on without having it. Then school started and I got my in the end of September.

the next time it occurred was in the end of November. And now it's January of 2017 and I still haven't gotten it!

note: I'd get a lot of cramps a month or weeks before my period occurring 

PLEASE HELP ME IM WORRIED