A girls period is usually irregular for a while, you just recently started, so it's going to take a while before it gets regular.
Or...if you've had sex, then you could be pregnant. But Im going to go with the first thing I said, as that is most likely what is going on. Dont get worried over it, unless you've had sex, because in time it will settle down.
I DO NOT GO ON HERE ANYMORE. I HAVE LEFT THIS PLACE FOR GOOD AND DON'T INTEND ON COMING BACK. PLEASE DON'T FRIEND REQUEST ME, PRIVATE MESSAGE ME, OR ANYTHING BECAUSE I WILL NEVER SEE IT AND YOU'LL NEVER GET A RESPONSE. THANK YOU.