While pleasure is a significant, if not primary, motivation for why people have sex, reproduction is another important incentive for many, as well as a potential consequence or risk of heterosexual sex that many of us have to navigate in our pursuit of pleasure. So, if you or your partner has a uterus, whether you want to figure out how to avoid pregnancy, or you’re eager to become parents, understanding this stuff is definitely worth your while. Let’s jump right in.
What exactly has to happen for someone to get pregnant?
When people have sex to get pregnant, a person with a penis ejaculates inside a person with a vagina, both hoping that conception—the fertilization of an egg by sperm—will take place.
We’ll learn about sperm and testes when we get to the external genitals of penis-owners in just a bit. But for now, let’s learn about where the eggs are, and how they are produced.
The ovaries are a pair of oval-shaped glands located on either side of the uterus that are responsible for the production of eggs and hormones. Ovulation occurs when an ovary releases an egg into an oviduct—also known as the Fallopian tubes. Each ovary releases an egg alternately every month.
The oviducts or Fallopian tubes are the tunnels via which the egg cells travel from the ovaries to the uterus. Conception, or the onset of pregnancy —meaning the fertilization of an egg by sperm—usually occurs in these tubes.
While many of us might mistakenly think that a person with a uterus can get pregnant any day of the month, in fact, pregnancy is possible only around the time of ovulation. However, while eggs can be fertilized up to around twenty-four hours after they are released, sperm can live in a vulva
owner’s reproductive tract for up to five days. Thus, many couples seeking to become parents often try to track ovulation by paying close attention to the vulva-owner’s menstrual cycle, scheduling sex on the days leading up to ovulation.
Unfortunately, estimating your cycle absolutely perfectly and figuring out exactly which days you’re most likely to be ‘fertile’ and which days you’re not, is easier said than done. We’re only ‘fertile’ for a few days every month, with our fertility declining as we get older. This means getting pregnant can often be quite a lot harder than it sounds when a couple actually starts having sex with the intention to get pregnant—but, ironically, it’s also why accidental pregnancies are very common too. Preventing pregnancy without using protection is quite a lot harder than it sounds. If you’re not trying to get pregnant, I’d recommend you always use protection.
But back to the eggs. If an egg is fertilized, it moves to the uterus, where it implants itself in the endometrium, or inner lining of the uterus, that has been prepped for its arrival. The uterus is the organ that is colloquially referred to as the ‘womb’. When a pregnancy occurs, it serves as home to the developing foetus.
Okay, so what is a period?
If an egg is not fertilized by sperm, it disintegrates in the fallopian tube within a few days. The endometrial tissue is then shed along with blood, and secretions from the vagina and cervix, as a ‘period’.
While most people think that the menstrual cycle is just the few days of monthly bleeding, or the ‘period’, in fact, the menstrual cycle is the entire span from the first day of your period till the first day of your next period, which is roughly a month.
And, as you may have figured out from what you’ve read here so far, it’s actually made up of two cycles that interact and overlap—one occurring in the ovaries and the other taking place in the uterus.
The first part of the cycle gets an egg ready to be released from the ovary and prepares the lining of the uterus. The second part of the cycle lays the groundwork for the body to accept a fertilized egg, or to shed the endometrial tissue and start the next cycle if pregnancy doesn’t occur.
A complex interaction of hormones serves as a sort of communication system between the brain, ovaries and uterus to keep the menstrual cycle going.
In the event that an egg is successfully fertilized and implanted, these hormones facilitate the complex choreography of maintaining and nurturing a pregnancy over roughly nine months, from conception to delivery.
If you don’t get pregnant, the body sheds the uterine lining and basically preps itself to try again with a new egg every month until menopause. (Unlike sperm which keeps being produced in the testes, people with ovaries are born with a finite supply of eggs—so we eventually have none left, and we stop getting our period and being able to get pregnant. More on menopause in a moment.)
