Menstrual Myths still continue. Stop me if you’ve heard this one. A woman can’t get pregnant if she has sex during her period, right? How about this one. A girl who has unprotected sex can’t get pregnant until after she gets her first period. Sound right? Women with regular menstrual cycles get their period on the same day every month. If only we could become so automated, as to make that one be true!

Wrong. Wrong. Wrong.

Let’s discuss 2 menstrual myths

The menstrual cycle technically begins on day one of bleeding and ends the day before bleeding begins again. Many of us mistake the “cycle” to refer to the days of bleeding only, but menstruation is just a setup for what follows, on average, over the next 28 to 32 days. When it comes to the length of menstrual cycles, we are all as unique as our noses, fingerprints, and personalities. 

Let’s visit menstrual myth #1

The first menstrual myth is that a woman cannot get pregnant if she has unprotected sex during her period. To understand that this is a dangerous misconception, we need to understand a few basics about ovulation, egg life, and sperm life.

Ovulation – the release of the egg from the ovary – is the “main event” of the menstrual cycle. It will happen at a moment in time mid-cycle. Without a sensitive blood test to measure hourly hormonal changes or actually observing ovulation with a camera (very rare and hardly practical!), a woman will not know when that moment occurs. 

menstrual myths

What we do know is that once it does occur, the egg will live, or remain viable, for 12 to 24 hours. We also know that following ovulation, the female body will set itself up to nourish that egg whether or not it has been fertilized. A thick, luscious lining filled with blood and nutrients will grow on the walls of the uterus. This is called the endometrium.

The body will maintain this lining, meant to nourish a fertilized, implanted egg, for 12 to 16 days. If a fertilized egg is not there, the lining will be shed and a woman will have her period. That’s where the blood comes from – the shedding of blood and nutrients that have lined the uterus to keep a fertilized egg healthy. 

Another number to consider. Sperm can live in the female reproductive tract for up to 5 days, depending on whether conditions are favorable or unfavorable to their survival. 

Let’s do a numbers re-cap:

  • Average menstrual cycles vary from 28 to 32 days.
  • Once ovulation occurs and an egg is released from the ovaries, it has a life span (unless fertilized) of 12 to 24 hours.
  • After ovulation, the female body will go through a phase during which a thick, nutritious lining will build up in the uterus. If pregnancy does not occur, that lining will be shed in 12 to 16 days.
  • Sperm can live in the female reproductive tract for 3 to 5 days. 

So. How does all this information come together for us?

Let’s work backward. Knowing that a 16-day phase will begin after ovulation, and end with menstruation, take your own average 28-day cycle and subtract those 16 days. That takes you to day 12 of your cycle.

Remember day 1 is the first day of bleeding. Ovulation will take place over a 12 to 24-hour period of time prior to the buildup of that endometrial lining, so take that day away and you are at day 11 of your cycle (and by the way, at your most fertile.) Now consider that sperm can live up to 5 days in your reproductive tract.

Let’s say you had intercourse 5 days before you ovulated and let’s do the math again…it puts you at day 6 of your cycle. Most women will bleed for 4 to 6 days…and bingo! You’ve had unprotected intercourse while bleeding, but at a time during your cycle when you are fastly approaching ovulation – the release of an egg, just waiting to be fertilized. Consider the 26-day cycle, and you are even more at risk for unintended pregnancy by having unprotected sex during your period. 

menstrual myths

Let’s visit menstrual myth #2.

Now that we know the sequence of events that lead to ovulation and the release of an egg from the ovary, we know that menstruation precedes ovulation, but only as a signal that ovulation has occurred. The shedding of the uterine lining means you have ovulated, but before you shed it for the first time, you will have ovulated for the first time. Thus, when an egg is in the female reproductive tract waiting to be fertilized, unprotected intercourse can lead to pregnancy in a young woman who has not yet had her first period. 

By far, the best way to best keep track of one’s cycle is to document the days of bleeding, and simply count forward until bleeding begins again. Just that simple act can teach volumes about ovulation and how to anticipate and prepare for your period. You will see patterns emerge.

There are apps that can make this easier, and then there is the old-fashioned calendar with a simple * to designate the days of bleeding. Of course, there are many other signs and symptoms of ovulation and post-ovulation (aka pre-menstrual) phases to learn about and document, but this simple act will demonstrate that your period never comes on the same day of the month. The 12th or the 22nd or the 30th. It doesn’t.

The months are not all the same length and your cycles will vary in length. If anything is “normal” maybe not feeling like a robot can be the most normal feeling of all.