How many days are suppose to be in between menstrual cycles?

Some girls have their periods for only 3 or 4 days, others as long as a week, sometimes longer. The menstrual flow of blood can vary from woman to woman also.

I know that... I was more wondering, when you end your perid, how many days should itbe to the next one?

Usually about 28 days

Mine averaged 38.7 days from the start of one to the start of the next for over 20 years. They lasted an average of 5 days. When I got an IUD placed, the cycle turned "normal" with only 28 days between and periods went for 7 days.

For some women, a period or two per year is normal. For some it may start every 3 weeks.