No period for about four months and no history of sexual activity?

I'm fourteen and have never had intercourse, but my period is really wacky. I knwo that some women have crazy periods where they may skip a few months and then get it again, then skip another few months and it's normal for them. I seem to be one of those people, as I feel perfectly healthy, have normal weight, no noteable pain (except for what I accidentally inflict on myself, but I mean that there's been no random pains or feelings of soreness), and it's been like that for two years. My period freaks me out though, as I'll skip what seems like so long, and then have it normally. Right now, it seems as if I've skipped about four months and I'm getting anxious about it as I usually do. It still worries me despite my tendencies, and I want to know if anyone has a suggestion of what might be going on with my body?