This is something every girl should know about her own body.

twogoldstars:

And yet my slow realization, after being consulted (as resident student nurse/health person ‘round here) numerous times about “can I get pregnant if…” is that most, or at least many girls, do not know this stuff. Which means it was never taught. Which means that someone, somewhere, decided that this was not relevant information to teach adolescent and adult women.

But knowledge is power, so here goes.

(last minute note: this is long ‘n stuff, but I decided to post it anyway because I really think it is important. I fervently hope you either a) already know this, or b) take the time to learn a little more right now).

This is how to determine your fertility window. To start off, your fertility window is the time surrounding ovulation, which means it is the window in which you are most likely to get pregnant.*

1. Your ovulation cycle is controlled by your hormones (estrogen and progestin, mostly), and it’s the rise and fall of these hormones that cause you to ovulate and then later menstruate. They also cause all the in-between stages that we usually ignore (but are also important.) This is why birth control pills work (but we’ll get there in a moment). For now, suffice to say that spikes and dives in different hormones trigger different reactions within your body.

2. Most women’s cycles last 28-32 days. If you know how long your cycle is, and you’re consistent, it’s even easier to track your fertilization window.

3. In a 28 day cycle, ovulation often occurs on day 14. this means that you ovulate 14 days after the START of your last period (NOT the end!). If you aren’t sure exactly how long your cycle is or your cycle isn’t totally regular, then you could estimate that your ovulation day is between day 12 and day 16.

4. But wait! There is more. If you’re having sex, you should know that ejaculated sperm can survive within the cervical/uterine environment for up to 3 days. This means that if you have sex 3 days before your ovulation day, you can still possibly get pregnant. So to find the beginning of your fertile window, subtract 3 from your ovulation day (for most of us, this is day 11, but let’s be conservative and say day 9).

5. Now, an unfertilized egg is only alive for 12-24 hours after it is released from the ovary. This means that you can get pregnant up to one day after your ovulation day. Therefore, you need to add one more day onto your ovulation day to find the end of your fertile window. For many of us, this is day 15 or 17.

6. So to conclude, most women’s fertile windows will fall somewhere from day 9 to day 17 after their last period began. If you have unprotected sex within that window, you have a reasonable risk of getting pregnant. If you aren’t having sex within that window, the chance of pregnancy is much, much less.**

This is the basis of natural family planning, by the way. But even if that’s not your preferred method of birth control (which really unless you’re doing it for religious reasons you should be using something more effective; this works about 60-70% of the time, which is about on par with the withdrawal method and misusing condoms) it’s still an important thing to know about your body.

A note about being on the pill: on most birth control pills, you are taking supplemental hormones that prevent your body from ever ovulating in the first place. So as someone once asked me, if you’re on the pill you cannot get pregnant from having period sex. It’s highly unlikely that you would get pregnant from period sex regardless of being on birth control, but if you’re on the pill there are no eggs involved. You are not ovulating. If you miss a pill or two or three, you need to look at all that paperwork that came with your medications to see if you are still covered. In some prescriptions, like mine, if you’re late on one day it doesn’t cause enough hormonal fluctuation to catalyze ovulation. But other prescriptions differ, and you should always check.

* This is the part where I point out that every girl and every girl’s body is miraculous and different. There are plenty of crazy pregnancy stories. I am not suggesting that y’all use this as a method of birth control. In fact, I very much discourage that. Also, condoms are great and you should be using them because hi! STIs are nasty things! Avoid them! But say your condom breaks— because that shit happens. What do you do? How bad should you be freaking out? Are you DeFiNiTeLy pregnant? Well, take a look at your fertile window. 

** This is the second part where I say that there are plenty of crazy pregnancy stories, and everyone should find a method of birth control that is affordable, effective, and that they are comfortable with using every time they have sex.

Know your body! Because your body is amazing, and every girl should know at least a little bit about how it works. And finally, Planned Parenthood is and always has been an incredible resource for learning about this stuff.

Well done, Allie. This is wonderfully written. Read up, ladies!