How to Use Natural Family Planning to Get Pregnant

To use natural family planning to get pregnant, you track your body's natural fertility signs to find your fertile window, then time intercourse for those days. The fertile window is roughly six days that ends on the day of ovulation, and signs like cervical mucus and basal body temperature help you pinpoint it. The same method women use to avoid pregnancy also works in reverse to help you conceive.

What is natural family planning for conception?

Natural family planning, also called fertility awareness, is a way of observing and recording the natural signs of your cycle to identify when you are fertile. To avoid pregnancy you steer clear of the fertile days. To achieve pregnancy you do the opposite and make the most of them. Popular sign-based methods include the symptothermal method, the Billings Ovulation Method, the Creighton Model and the Marquette Method, and each gives you a practical way to recognise ovulation as it approaches.

When are you most fertile?

You are fertile for only a short stretch of each cycle. A landmark study by Wilcox and colleagues found that conception occurred almost entirely within a six-day window that ends on the day of ovulation (Wilcox et al., 1995). The chance of conceiving from a single day of intercourse rose from about 10 percent five days before ovulation to around 33 percent on the day of ovulation itself. In practice the two to three days before ovulation and the day of ovulation are your best opportunities.

Why is the fertile window only about six days?

Sperm can survive in fertile cervical mucus for up to five days, while an egg lives for around 12 to 24 hours after ovulation. That combination is what gives you a window of roughly six days. Fertile-type mucus is what keeps sperm alive and helps them travel, which is why the days leading up to ovulation matter so much.

How do you find your fertile window?

Two signs do most of the work, and using them together is more reliable than either one alone. This pairing is the basis of the symptothermal method.

Cervical mucus

As ovulation approaches, cervical mucus becomes clear, slippery and stretchy, a little like raw egg white. This fertile-type mucus is a strong signal that your most fertile days are here or close. Research by Bigelow and colleagues found that the quality of cervical mucus was an even better predictor of conception than the exact timing of intercourse relative to ovulation (Bigelow et al., 2004). When you notice this kind of mucus, you are in your fertile window.

Basal body temperature

Your basal body temperature is your resting temperature, taken first thing in the morning before you get up. After ovulation it rises by around 0.3 degrees Celsius and stays up until your next period. Temperature confirms that ovulation has happened, but only after the fact, so it is best used alongside mucus, which gives you notice beforehand. Charting your temperature over a few cycles also helps you learn your own pattern.

How do you time intercourse to conceive?

Once you can recognise your fertile window, timing becomes simple. Aim for intercourse on the days you notice fertile-type mucus and continue through to the day your temperature rises. Having intercourse every one to two days across the fertile window is a common approach and helps you cover your most fertile days without second-guessing the exact day of ovulation. There is no need to save up or follow a rigid schedule.

How long does it take to get pregnant this way?

For most couples without known fertility problems, focusing intercourse on the fertile window works within a handful of cycles. In a German prospective study of 346 women using natural family planning, the cumulative chance of pregnancy was about 38 percent after one cycle, 68 percent after three, 81 percent after six and 92 percent after twelve cycles (Gnoth et al., 2003). Identifying your fertile window can shorten the time it takes to conceive compared with leaving it to chance.

When should you talk to a doctor?

Fertility awareness is a helpful first step, not a substitute for medical care. It is generally worth seeing a doctor if you are under 35 and have been trying for 12 months, or if you are 35 or older and have been trying for 6 months. Speak to a professional sooner if your cycles are very irregular or absent, if you have a known reproductive health condition, or if you simply have concerns. Tracking your signs gives your doctor useful information to work with.

How Majella helps

Majella is a cycle and fertility tracking app made for women who want a natural, private approach. You can record your cervical mucus, basal body temperature and cycle each day, and Majella helps you see your fertile window so you know when to time intercourse. Cycle tracking is free, the more advanced natural family planning features are available on the paid plan, and your data stays private on your own device rather than on a company server.

Frequently asked questions

Can natural family planning really help me get pregnant?

Yes. The same fertile signs that tell you when to avoid pregnancy also tell you when you are most likely to conceive. Timing intercourse to your fertile window gives you the best chance each cycle.

What is the best sign for predicting ovulation?

Cervical mucus is the most useful sign for predicting ovulation before it happens, because it changes in the days leading up to it. Basal body temperature is valuable too, but it confirms ovulation after the fact, so many people track both.

How often should we have intercourse when trying to conceive?

Every one to two days during your fertile window is a common and effective approach. This covers your most fertile days without needing to pinpoint the exact hour of ovulation.

Can I use natural family planning if my cycles are irregular?

Often yes. Because sign-based methods respond to what your body is doing now rather than assuming a set cycle length, they can still identify your fertile window when cycles vary. If your cycles are very irregular or absent, it is worth checking in with a doctor.

References

Wilcox AJ, Weinberg CR, Baird DD. Timing of sexual intercourse in relation to ovulation. New England Journal of Medicine. 1995;333(23):1517-1521.

Gnoth C, Godehardt D, Godehardt E, Frank-Herrmann P, Freundl G. Time to pregnancy: results of the German prospective study and impact on the management of infertility. Human Reproduction. 2003;18(9):1959-1966.

Bigelow JL, Dunson DB, Stanford JB, Ecochard R, Gnoth C, Colombo B. Mucus observations in the fertile window: a better predictor of conception than timing of intercourse. Human Reproduction. 2004;19(4):889-892.

Stanford JB, White GL, Hatasaka H. Timing intercourse to achieve pregnancy: current evidence. Obstetrics and Gynecology. 2002;100(6):1333-1341.

A note on this article

This article is for general education and is not medical advice. It is not a substitute for personalised guidance from a qualified healthcare professional. If you have questions about your fertility, your cycle or trying to conceive, please speak with your doctor.

Related reading: What Is Natural Family Planning? A Complete Guide and How to Track Your Cycle with Basal Body Temperature and Cervical Mucus.