You can get your period much later on as this varies from one individual to another based on hormones. Some girls get to start puberty at the age of eight while others begin as late as 13 or 14 years. You just need to be patient. Read more from http://kidshealth.org/kid/talk/qa/when_period.html.
Hi, Katy. Don't worry, honey. My best friend in high school was close to 15 when she got hers. I don't want to sound negative here, but once you start, you'll count your blessings you started later than others! It's nothing to worry about, sweetie. You'll start when your body's ready.
Everyone is different and things happen at their own pace. Trust me, it's not something to look forward to. :| you'll hate it when you get it. I'd say average when you should get it is around 13/14 sometimes 15. but some people get it as early as 9 and as late as 18 so don't worry, it will happen eventually.