Welcome to brain Stuff, a production of I Heart Radio. Hey brain Stuff. Lauren Vogelbaum here, considering that roughly half the people on the planet experience periods during their lives, there are a lot of myths out there about periods, and there are a lot of myths about conception and pregnancy. Today, let's best a myth that has to do with all three. You may have heard it before. You can't get pregnant during your period. This is not true. You can totally
get pregnant during your period. It's not super likely statistically speaking, but just as a baby's arrival isn't as simple as a stork dropping off a special bundle, getting pregnant involves plenty of biological intricacies and uncertainties. A menstrual cycles vary, and a person can technically get pregnant at any point during their cycle. The typical menstrual cycle lasts twenty eight days,
split into the folicular and luteal phases. In a nutshell, the folicular phase consists of an egg developing in the ovaries and the uterus starting to grow a nurturing lining. Then the egg releases. That's ovulation, and the luteal phase begins. It's the preparatory time in which a person's body gets ready for that egg to meet up with a sperm in the fallopian tubes. Hormone secretions prompt the uterine lining
to continue thickening for embryo implantation should fertilization occur. If fertilization does not occur, menstruation commences as the lining of the uterus sheds and the unfertilized egg exits the uterus. If you have a textbook twenty eight day cycle with a textbook five day period, you are probably most likely to get pregnant. If you have sex fourteen days after your last period. That's when sperm are most likely to encounter a mature egg in the fallopian tubes. But not
all cycles last twenty eight days. Not all periods last five days. The normal range for a menstrual cycle is anything from twenty one to thirty five days, and the
average period can last from four to seven days. It's normal to reach peak fertility anywhere from eleven to twenty one days after your last period, and that's not even taking more outlying situations into consideration, irregular periods that only come around every few months, as well as cycles that are shorter than the average twenty eight days, may hold higher probabilities for overlap between ovulation and menstruation, although the
statistical chances of it happening are low. There are three main ways that it's possible to get pregnant from unprotected sex despite the presence of vaginal bleeding. First step, if a woman has an especially short menstrual cycle, ovulation can occur before menstruation stops. This is the least likely scenario for a period pregnancy to take place, but a longer period lasting up to seven to eight days, combined with a compressed menstrual cycle can add up to an embryo.
More commonly, with shorter menstrual cycles, the ovaries could release an egg a few days after menstruation finishes. But even though an egg wasn't ready and waiting during the period itself, unprotected intercourse on say the last day of bleeding, could leave behind sperm with a surprisingly potent shelf life. A sperm can survive inside a woman's body for three to five days, possibly resulting in pregnancy if the ovaries release an egg into the flopian tubes in that time frame.
Vaginal bleeding can also be misleading, as it doesn't always signal menstruation. In fact, some women's spot during ovulation, which could be mistaken for a light period. In that case, unprotected sex could certainly result in pregnancy. Stress, for example, can be the culprit behind a late period, as can travel, which can sometimes be synonymous with stress. Change in weight can affect a person's peer it, and so can illness.
Certain conditions and some medications. For example, take endometriosis, which is a case of misplaced cells. Ones that should be in a person's uterus grow in other places to or instead. Like the bowel, fallopian tubes, and ovaries. They respond to menstrual hormones by swelling and getting thicker, just like the ones that make up the uterine lining, but they don't
get shed. They're just stuff. This condition can cause shorter cycles, longer periods, or breakthrough bleeding and cramping, all making it more difficult to know what stage of your cycle you're on. Or take polycystic overy syndrome or PCOS. This is caused by your hormones being out of whack, and since the menstrual cycle is ruled by hormones, it can cause your periods to come irregularly, or uterine fibroids, which are non
cancerous tumors in the uterus. They can change the shape of the uterus and cause extra heavy periods or p the inflammatory disease, which is an infection often caused by bacteria from s t i s like chlamydia. While some people have no symptoms at all, it can result in irregular periods or damage to the fallopian tubes, which messes with eggs and sperms travel through the reproductive system. All of that is to say that our bodies are all different,
and sometimes they're up to some pretty weird stuff. It's plausible for an expectant egg and an enterprising sperm to meet at any point during the month. Also, while we're here dispelling the myth that you can't get pregnant on your period, let's talk briefly about another myth. Some people mistakenly think that urinating after unprotected intercourse will flush any
lingering sperm from the vagina. That's anatomically impossible, though, the since sperm enter through the vaginal opening, whereas urine exits through the ureical opening, which is between the vaginal opening and the clitteress m Today's episode is based on the articles Can a Woman Get Pregnant during her Period? By Kristen Conger and Abnormal Menstrual Cycles and Fertility by Katie Lambert,
both on how stuff Works dot Com. Brain Stuff is production by Heart Radio in partnership with how stuff Works dot Com and is produced by Tyler clang Fully. More podcasts my heart Radio, visit the I heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.