Count day 1 as the first that you bleed (not the first of the month but first day of bleeding).
If you have a standard 28 day cycle you will usually ovulate around day14 (note this is not the 14th of the month but day 14 from when you start bleeding).

Ok now lets remember sperm can live for about 5 days inside you and once you ovulate the egg is viable (good) for about 36 hours.

So 14 minus 5 days (for sperm life) = 9
and 14 add 2 days (for egg viability) = 16

days 9 - 16 are your "high" fertility days. However, this method is better for getting pregnant and not for avoiding it as you can't be 100% sure when you ovulate. Using such an approximation you must assume that you are likely to become pregnant and also remember you are not protected against disease.
Some women have unusual cycles and ovulate during their period.
Usually ovulation happens 14 days before bleeding begins so if you have say a 35 day cycle ovulation would typically be around day 21
21 minus 5 days = 16
21 add 2 days - 23 so days 16-23 are your high fertility.

Wow that can be confusing lol

Starting to count on the first day of your period the 14th day is typically when a girl ovulates and the most fertile day. Keeping in mind that sperm can live for about 3 days inside the female body (i'm pretty sure but I might be wrong so google it) the 11th 12th and 13th day aren't safe. I'ld throw the 15th and 16th on there just to be safe also : p. There is actually only 12 hours during a girls cycle where she can get pregnant. Personally I wouldn't use this rhythm method to prevent pregnancy as a cycle can be unpredictable and can change. Or you could make a prediction error. I recommend using other contraceptive methods. : p

While I was writting that up the post already got answered : p oooopps. And there I was thinking I could be helpful. :cry: :lol:

Lol yeaaaaaah get on the pill or the patch and use a condom too just in case, if you don't want a baby.

The safe days are the days that you use a condom and get on birth control... = wink wink =