[Sparki]

I'm a girl.

First of all to be remotely accurate at this Keep track of the first day of your menstrual cycle for eight months to a year The time between the start of each new period is the length of your menstrual cycle for that month.

Then to get a general "unsafe" time. subtract 18 from the length of your shortest cycle For example, if your shortest cycle was 26 days, the first 'unsafe day' of your period would be (26-18 = 8) eight days after your period starts. Then subtract 11 from the length of your longest cycle For example, if your longest cycle was 30 days, the last 'unsafe day' of your period would be (30-11 = 19) 19 days after your period starts

So to not get pregnant no sex 8 days after your period starts to 19 days after it starts.

And a Basal Thermometer needs to be used first thing in the AM before you even get out of bed. You will need to track your temps every day for a few months. Your lowest temp is your ovulation day. then you have to do egg/ sperm life cycle math.

And none of this is close to being 100% Accurate.

Birthcontrol FTW