Most often, no. The supposed "normal" length of a menstrual cycle is 28 days but most women will have shorter or longer cycles.
Period can arrive anytime after the withdrawal bleed from 4 weeks to 8 weeks. Its different in every woman.
Not your actual period, but you can have bleeding, sometimes even every 4 weeks, caused by background hormones that mimic your body's normal cycles.
NO.
Bi-Weekly = every 2 weeks - Every payroll period will cover 2 weeks. Bi-Monthly = 2x per month - Every calendar quarter will have one payroll period that has 3 weeks in it.
You should get you period about once a month, every four weeks or so.
4 weeks
From the start. You count the first day of bleeding "day 1".
Your supposed to get it every four weeks or 28 days and its light at the last thre days because your finishing your period
If you are experiencing your period every two weeks, it could indicate some very serious problems. You need to make an appointment to see your gynecologist as soon as you can to get it checked out.
About 4 weeks.
2-4 weeks
No, it just means your period isn't stable just yet. I used to have my period twice a month before I got on birth control to regulate it. It doesn't mean you're pregnant just because you're getting your period every 3 weeks instead of every 4 weeks.