It has come to my attention that a lot of women out there who don’t currently want to get pregnant are pretty misinformed about how you can use the Fertility Awareness Method as natural birth control. Quite a few people have asked me if FAM isn’t the same thing as the Rhythm Method—AKA an outdated, ineffective method that’s caused a whole lot of unplanned pregnancies! Come on, do you really think that’s what we’re all about? :)
Granted, if you’re not familiar with FAM, the idea of having unprotected sex without being on the Pill or another form of hormonal birth control may cause some anxiety. I’ve heard a lot of women express that they would really prefer not to be on hormonal birth control, but they’re just not confident enough about their ability to use FAM effectively, whereas they know they can rely on the Pill.
Well, ladies, I’m here to let you in on something. The Fertility Awareness Method IS effective as a method of birth control (99.4% effective, when used correctly)—and it’s easy! It only takes a few minutes a day, and it's totally natural and free (other than the cost of a thermometer, I guess.) Plus, it’s just cool to learn about how your body works and how you can work WITH your body to achieve your fertility goals, rather than leaving that up to a pill or an IUD. Also, if you do decide you want to get pregnant at some point, being aware of your fertility signs will make it much easier for you to conceive.
So, how do you use FAM as birth control? First, you need to know about your cervical fluid and basal body temperature. You may also want to learn about cervix tracking. Then, you need to memorize the 4 rules of using FAM as birth control (explained below), which outline when you're fertile and when you're not. Outside of the fertile window, it’s impossible for you to get pregnant!
Note: Before relying on FAM as birth control, you should chart your signs for a few cycles so you have a clear understanding of your fertility signs and how they change throughout your cycle. We also recommend that you read a book about FAM, take a class, and consult with a fertility awareness instructor so that you understand EVERYTHING about FAM. You don't want to take any chances, right?
So, here they are - the 4 rules of using FAM as birth control:
1) First 5 days rule—You are generally considered infertile the first 5 days of your menstrual cycle, unless you have ever had a cycle that was less than 25 days long.
During your cycle, there are typically 6 days when you are fertile. This is due to the combined fertility of a couple: whereas an egg will only survive for 12-24 hours after being released from the ovary, sperm can survive in fertile cervical fluid for up to 5 days.
During the first five days of your cycle, your body probably isn't producing fertile cervical fluid, and ovulation is likely too far off for sperm to be able to survive until it occurs. So, you are considered infertile during that time. This rule applies regardless of how many days your period lasts. Any bleeding after the first five days of your cycle should be considered fertile, as the blood could mask fertile cervical fluid.
Note: This rule applies only if you observed a clear BBT shift 12 to 16 days prior to the start of your cycle. This confirms that the bleeding you experience is your period and not abnormal bleeding or ovulation spotting.
If any of your cycles in the past 12 months have been less than 25 days, you should consider yourself infertile for only the first 3 days of your cycle. This is to avoid the risk of getting pregnant due to early ovulation. Also, women who are beginning to experience signs of menopause should not rely on this rule, as they can experience major hormonal changes that could cause early ovulation.
If you experience spotting after your period ends, don’t assume you’re still infertile. Some women experience ovulation spotting, or spotting just before or during ovulation. Ovulation spotting, which is thought to be due either to a surge in estrogen levels or as a result of the egg rupturing through the follicle as it is released from the ovary, is actually considered to be very fertile cervical fluid.
A chart highlighting the first 5 days rule (Note: Solid heart=unprotected sex, heart outline=protected sex)
2) Dry day rule—You are generally considered infertile the evening of any day you observed that you had no cervical fluid.
The quantity and quality of your cervical fluid is key to whether you are fertile or not. Without cervical fluid, the vagina is very acidic, with a low pH of around 3-4. Because sperm requires a more alkaline environment (such as semen) to survive, it typically will not survive in the vagina for more than 1-2 hours if cervical fluid is not present. So, if there’s no cervical fluid, you’re not fertile. However, you need to wait until the evening to have unprotected sex to make sure your body doesn’t produce potentially-fertile CF during the day. FYI - arousal fluids and lubricants do not provide an environment in which sperm can survive, unless of course you're using a lubricant specifically made for sperm capacitation (but you're prooobably not doing that if you're using FAM as birth control, right??)
If you only experience one or two consecutive days of sticky cervical fluid and then revert back to dry days, you are considered safe again the evenings of each dry day. But note that this means if you ever observe creamy or eggwhite cervical fluid, you should NOT consider yourself safe even if you have a dry day afterwards.
Sometimes, residual semen from intercourse can mask the presence of cervical fluid. So, if there's any semen present in the vagina the day after intercourse, you should consider yourself potentially fertile, to be safe (to eliminate semen from the body so this doesn't happen, you can do Kegels exercises after intercourse).
Note: Women will almost always experience a slight moistness at the vaginal opening. You're still considered dry if there's no cervical fluid present (how do I measure cervical fluid?).
A chart highlighting the dry day rule
3) Peak plus 4 rule—You are generally considered infertile the evening of the 4th day after your most fertile cervical fluid and once your CF has become infertile again, and you have observed a clear BBT shift.
As you approach ovulation, your cervical fluid will generally progress from Dry --> Sticky --> Creamy --> Eggwhite --> Watery as it becomes more fertile. The wetter your cervical fluid, the more fertile it is. After ovulation, your CF will begin to dry up. The last day of wetness that you experience before you begin to dry up is your Peak Day - generally the point during your cycle at which you are most fertile. Note that I said the Peak Day is your LAST day of wetness, and not necessarily the day of the MOST wetness - so if you have lots of watery CF on one day, then a little watery CF the next day, and then sticky CF the following, the second day (with a little watery CF) would be your Peak Day.
You need to wait until the evening (6 PM or later) of the fourth day after your Peak Day until you can consider yourself infertile. This is because it's possible that you won't begin to ovulate until two days after your Peak Day. At ovulation, it's possible to release two eggs within 24 hours of each other (this is how fraternal twins are conceived), and since each egg can live a maximum of 24 hours, this adds up to 4 days after the Peak Day.
Note: women with Polycystic Ovarian Syndrome or other hormonal disorders can sometimes experience ‘false peaks’ in which their cervical fluid builds up from infertile or less fertile (sticky) to fertile (eggwhite/watery) and back to infertile again, but ovulation does not occur. This is why it’s especially important to keep track of your BBT as well as your cervical fluid, so that you can confirm ovulation.
A chart highlighting the peak plus 4 rule
4) Temp plus 3 rule—You are generally considered infertile the evening of the 3rd day after your BBT shift.
A BBT shift that is sustained for at least 3 days confirms that ovulation has occurred. You need to make sure the BBT shift is sustained for at least three days because it's possible that you won't ovulate until 24 hours after your temperature shift, and again, it's possible to release two eggs within 24 hours of each other (this happens 10% of the time, so don't take your chances!). Also, you'll want to ensure that the rise in your temperature was due to ovulation and not to something else, such as drinking alcohol the night before, fever, lack of sleep, etc. Look for three consecutive temperatures above your coverline. Once a sustained BBT shift has occurred, you are considered infertile for the rest of your cycle.
A chart explaining the temp plus 3 rule
So, there you have it! Once you get the hang of tracking your fertility signs, you can have unprotected sex during your infertile days, and either abstain or use a barrier method of protection, such as condoms, during your fertile days. (Of course, it’s always a good idea to use condoms with new partners, whether you’re in your fertile window or not!) If in doubt, assume you’re fertile.
For more info, check out this cool video we made about using FAM as natural birth control. Feel free to show it to your skeptical or misinformed friends!
Also, watch Kindara co-founder Kati Bicknell talk about transitioning from the Pill to the Fertility Awareness Method.