Assuming you mean the menstrual cycle its about every 28 days. and usually begins between 12-14.
7 weeks
Wish I knew sorry hun
There are no days before your period, when you already are pregnant. As soon as you are pregnant your next due period at the 4th will not come. When you are without periods for 2 months, it is very likely that you are pregnant. Many women don't know, that after 10 days after their last period, they are in a period of another 10 days that hey can become pregnant. Mostly it is only 7 days. So that means that 21 days between your period you cannot become pregnant. Short: Period + 10 days free. + 8 days pregnancy possible. + 10 days free. Dr. Phylopi
14 days before your period starts.
well i dont think that you can have a period for twenty days and if you do you should go to the doctor
28 days
15 days
It takes 28 Earth days. It is a period called a 'Lunar month'.
28 days
A normal period can be 3-7 days long.
Five days after menustrial cycle
Mars period of revoultion around the sun, its orbit, is 686.971 Earth days long.