When did you start having your period? If you just got it for the first time a few months ago, you're fine. When I first got my period, it only happened every three months for the first year. However, if you have been having your period for over a year, something may be wrong. Wait about a week, and then if you still haven't has it talk to your mom or a doctor. Hope I helped:)
If you're not sexually active, you're just missing a month. I wouldn't complain about it much since that sounds like a nice treat. If you are sexually active, go see a doctor or pee on a pregnancy test. Or, if you are under- or over-weight, you could just be having a funky period, which can happen often for either of those.
Well pregnancy of course, but if your not sexually active ( like me ) then it's just an irregular period. It happens to me and all my girlfriends all the time. Skip a month, get it twice, cramps with no blood, heavy, light, ect. You will be ok no need to see a doctor unless you have risk of pregnancy