No one can say exactly when you'll get your first menstrual period, but it will be sometime during puberty. Puberty is the time in your life when you begin to become an adult. This means a lot of growing and changing — both inside and out. Some girls start puberty at age 8, and others may start as late as 13 or 14.
http://kidshealth.org/en/kids/when-period.html
Skin Issues. Extra acne tends to pop out on your face when your period shows up because your hormones are goin’ wild. You could also get some cold sores and sometimes swelling in your face, hands, and feet. If your boobs hurt a bit and are tender, that’s normal, too. Problem City.
http://www.girlslife.com/fitness/your-bod/18690/5-signs-your-period-is-coming
You will start getting a white sticky liquid in your pants this is called discharge(in your pants it will go hard and crusty). Soon this will start to turn brown but this could take from 2days to 2 years (the brown stuff is dry blood). Do not worry though it is not harming you it just means that you are a lady now.
http://www.answers.com/Q/When_do_you_know_your_going_to_start_your_period_for_the_first_time
If your periods have been irregular, there are still ways you can pin ‘em down, even without a trusty calendar. Here are four signs that your bod gives a few days in advance to let you know when Aunt Flo is on her way.
http://www.girlslife.com/fitness/your-bod/18690/5-signs-your-period-is-coming
The thought of getting your first period can be pretty scary - and it gets even more overwhelming when it actually happens. But, the good thing is that every girl has to go through it at some point and the process can be made a lot less frightening if you know how to prepare for it.
http://www.kidzworld.com/article/816-getting-your-first-period
Keep a Record. You need to count the number of days between the first day of your period and the first day of your next period. This determines your cycle length, which for most women is 28 days, but it can be anywhere between 25 and 35 days. Once you know the first and last days of your period, keep a record of it. Highlight these days on a calendar to get an idea of when your next period might come.
http://www.newhealthadvisor.com/How-to-Know-When-Your-Period-Is-Coming.html
You may get your first period and then not have another for a few months. As you get older, your cycle will become more regular — usually between 21 and 34 days in length. The amount of blood you lose during your period can vary, too. It can seem like a lot, but typically it's only about 2 tablespoons.
http://kidshealth.org/en/kids/when-period.html
To prevent you leaking during your period you could use a sanitary towel or a tampon. Always tell your mother when you have started you period and never use a tampon for the first time without your mom. Always take sanitary towels or tampons everywhere with you. When you are swimming always use a tampon.
http://www.answers.com/Q/When_do_you_know_your_going_to_start_your_period_for_the_first_time
A Girl's First Period: Hurry Up Already! It can be frustrating when it seems like you're the last one of your friends to get your period. The thing is, everybody's bodies develop at their own pace and it's highly unlikely that you and your best bud will start your periods at the exact same time.
http://www.kidzworld.com/article/816-getting-your-first-period
A Girl's First Period: A Regular Visit. When your first period finally arrives, don't be too worried if it doesn't stick around for long. It can sometimes take your body a few months or even a few years to get into a regular pattern. Periods usually come every 28 to 30 days and last for three to seven days.
http://www.kidzworld.com/article/816-getting-your-first-period
how can you tell that your going to start your period
It will be sometime during puberty. Puberty is the time in your life when you begin to become an adult.