usually between the ages of 10 and 14, but everyone is different. some girls start at age 9, others at 15. i read a story about a girl whose period didn't start until she was seventeen. mine started when i was eleven. if you start a little earlier or later, do not worry about it :)
Nothing specific. Just the beginning of periods.
no i had mine at 11
an eon
a drought.
Possibly.
144 mya
20 mins
there is actually no way you can start your period faster
1900 to 150 B.C.
The fall of Rome in 410AD
nnnnnnnnnnnnnnnnnnnnnnnnooooooooooooooooooooooooooooo
89 years