How is a woman's cycle measured?

Question

According to http://www.americanpregnancy.org/gettingpregnant/understandingovulation.html it states "A woman's monthly cycle is measured from the first day of her menstrual period until the first day of her next period. " Some websites are stating that it is the first day of your period until the first day before your next period is to start. Which is true?

Answer 1

There really isn't an exact way of measuring cycles because some women measure from the first day of their period to the first day of the next. Some women measure from the first day of their period to the first day before their next period. Some women have 28 day cycles and some women have 34 day cycles and some women are in between. All women are different and views of cycles are different. I also use the second measurement you stated. It seems to be more accurate. In my opinion my cycle starts the first day of my period and ends the day before my next period. It just seems more logical.

Answer 2

I used to check mine using your second option. If you count day 1 again you are adding a day, do it from day 1 to the day before your next period.

Answer 3

Use mymonthlycycles.com for the best information.