One of the best ways to protect yourself from an STI is to be able to trust the person you’re having sex with. Luckily, trust is one of the many benefits of being in a long-term, committed relationship, and if both people are monogamous, there is very little chance of either person catching anything surprising.
However, for heterosexual couples, there is another way sex can surprise you. Sometimes it’s a pleasant surprise, but it also has the potential to ruin your life. I am talking, of course, about making another human being. A baby. Or babies.
All of the techniques you use to protect yourself from STIs can be used to protect yourself from being a mother or father as well. But if you and your partner are stable and not worried about STIs, there are at least three methods that may prevent any sperm from getting near an egg, without requiring you to spend a dime.
The most effective of these three methods scarcely counts as a birth-control method at all, since it requires the woman to already have been pregnant. The production of breast milk can suppress ovulation for up to six months and ensures that women don’t give birth to more children than they can care for. However, since it is impossible to use breastfeeding to prevent any pregnancies at all, couples usually use other methods.
One method that is considerably easier to use is the fertility awareness, or “rhythm” method. The secret behind this method is that a woman can only become pregnant if an egg is present at the time of sex. This is only true for a few days after ovulation, so if sex is avoided or protected with a barrier device on those days, pregnancy should be nearly impossible.
The difficult part of this method is determining which days are safe, since there are no obvious signs when a woman ovulates. It is marked by a slight change in body temperature and a change in the consistency of the mucous discharged by the cervix, and if these are recorded every day, the day of ovulation may be obvious.
However, it is much simpler to record which day menstruation begins, as ovulation usually occurs fourteen days before that date. If every woman had a 28-day menstrual cycle, the method would be easy. Since this isn’t true, it is important that the cycle length is known, so that the date of ovulation can be predicted. If a woman’s cycle is irregular, such as with many teenagers, then the rhythm method is probably not accurate enough to be effective.
Even less effective is the third method, withdrawal or “coitus interruptus,” in which ejaculation does not occur within the vagina. This theoretically prevents any sperm from entering the uterus, but not only are sperm present in precum, which is emitted well before ejaculation, but the method is incredibly dependent on the self-control of the man. If he doesn’t withdraw in time, and hundreds of nerves in a man’s body try to prevent him from doing so, then the method is not effective in the slightest.
These methods are risky. There is no latex or polyurethane protecting the egg from sperm and no protection from STIs at all. Also, lactation is largely impractical, and withdrawal is prone to error. However, for people in relationships where STIs are not a worry, but pregnancy is, fertility awareness can be an inexpensive and simple solution to their quandary.