Is there a phase of the cycle where you can have sex without getting pregnant? Spoiler: no

We are back again, talking about mysteries, secrets, taboos and myths surrounding the menstrual cycle. We will also address this topic during the Menstrual Cycle Festival, taking place in Milan from May 22 to 24 at Rob de Matt, and you can register here. Today’s topic is a delicate one: the menstrual cycle and sexual activity, combined. Despite widespread beliefs, there is no phase of the menstrual cycle that guarantees unprotected sex without the risk of pregnancy. The reason is simple: the human reproductive cycle is not a perfectly predictable system, and fertility can vary even in cycles considered regular, whatever that may mean.

Is there a phase of the cycle where you can have sex without pregnancy risk? Spoiler: no

First point: the fertile window is not a fixed point

Pregnancy can only occur when ovulation is present, meaning when the ovary releases a fertilizable egg. However, this phase is not always stable within the cycle calendar. According to medical sources, ovulation is variable and not fully predictable, even in people with regular cycles. In addition, sperm can survive in the female reproductive tract for up to about 5 days, meaning that intercourse occurring days before ovulation can still lead to pregnancy. This expands the so-called “fertile window” beyond the single day of ovulation.

"Safe days" are not truly safe

Calendar-based methods or fertility tracking methods, such as the so-called rhythm method, are considered unreliable as a sole form of contraception. Estimates show that fertility awareness methods can have significant failure rates in typical use. This happens because ovulation can shift earlier or later, cycles can vary due to stress, health, or hormonal changes, and body signals are not always precise. In other words, even “theoretically safe days” are not truly safe.

Unprotected sex always carries a risk

Health authorities emphasize that any unprotected sexual intercourse can carry a risk of pregnancy, even if it does not occur during the fertile window. The risk is not always high, but it is never zero. Three main factors make it impossible to fully eliminate the risk: sperm survival (up to 5 days), variable and unpredictable ovulation, and errors in natural tracking methods. For this reason, even perfect cycle tracking cannot guarantee absolute safety.

Guidelines and risk: contraception is the only reliable way

Major health organizations consider contraception the only reliable way to reduce the risk of pregnancy, especially in occasional or unplanned sexual encounters. Even natural methods, when used correctly, require abstinence or protection during potentially fertile days to reduce risk. There is no "risk-free moment" in the menstrual cycle. Fertility does not follow a rigid calendar and can change from one cycle to another. For this reason, every unprotected sexual encounter carries a possibility - however small - of pregnancy. The difference between cycle days is not between safe and unsafe, but between higher and lower risk.