Combinging charting with condom use is an excellent method, if your cycles have regulated, and you use it as so:
- during most fertile periods, abstain from procreative sex completely.
- during less or infertile times, use condoms for all genital contact.
In short, the only reliable way to chart is using a combination of tracking your cervical mucus and measuring your basal temperature daily. After a few months (and doing so continually) you'll likely be able to geta good bead on when you're most fertile.
We can't tell you what your safest and least safe times are because that varies from woman to woman. How you determine that for you is via the above methods, and there are books you can pick up to learn how to do so like Taking Charge of Your Fertility: The Definitive Guide to Natural Birth Control, Pregnancy Achievement, and Reproductive Health by Toni Weschler.
Charting can become a routine, but it's not the simplest thing there is, and there are other nonhormonal backup methods, like the diapragm or cervical cap available should it prove too taxing.
Editor and Founder, Scarleteen
My epitaph should read: "She worked herself into this ground."
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