When you decide it’s time to try and get pregnant (you might see it abbreviated as “TTC,” for “try to conceive” on blogs or fertility apps), it’s a good idea to go back to high school health class and brush up on your knowledge of ovulation and the female reproductive cycle.
A quick refresher: the reproductive, or menstrual, cycle is the hormonal process a woman’s body goes through each month to prepare for a possible pregnancy. We’ll walk you through the whole monthly cycle, including when your “fertile window” is, so that you and your partner know what to expect to increase your chances of getting pregnant. After all—timing is everything when trying for a baby.
How Long Is a Normal Menstrual Cycle?
The first thing to keep in mind: while the typical menstrual cycle is about 28 days long, every woman’s cycle is different. Some ladies’ cycles may even vary in length from month to month. As long as your period comes every 24 to 38 days (with Day 1 counted as the first day of your last period, and the final day being the start of your next period), it’s considered “normal” in length. Especially after stopping birth control, it’s helpful to keep track of your cycle to understand what your normal is. There are a lot of great apps that can help you understand your cycle (and even try to pinpoint your specific day of ovulation), however using a regular calendar works, too.
Days 1-8: Menstruation and Follicle Development
You can begin counting your cycle on the first day of your period. Throughout your cycle each month, the lining of your uterus builds up to prepare for a potential pregnancy. If you don’t get pregnant, your estrogen and progesterone hormone levels begin to fall. When they reach their lowest point, this signals to your body to begin menstruation (your period). This is the stretch of time when the blood and tissue lining of the uterus begin to leave your body. Typical period lengths are around 4 to 8 days.
Your body is up to some other reproductive tasks during the first days of your cycle, too. Typically, over Days 1-5, fluid-filled pockets called follicles begin to develop on your ovaries, with each follicle containing an egg. Between Days 5-8, one follicle continues to grow larger while the others are absorbed back into the ovary. As this large follicle grows, it causes the levels of the estrogen hormone in your body to continue to rise. By Day 8, period bleeding usually stops and these high estrogen levels start to make the uterine lining thicken again—the blood and nutrients in the thickening lining create the perfect location to nourish an embryo.
Days 9-14: Ovulation and the Fertile Window
A few days before the Big Day (Ovulation Day, of course), estrogen levels are at an all-time-high and cause a sharp rise in the luteinizing hormone (LH). This causes the fully-mature follicle to burst and release the egg from the ovary (this release typically occurs right around Day 14). This timeframe, known as the Fertile Window, is the time to try and get pregnant! Chances of pregnancy are highest if you have sex on the day you ovulate, but are also fairly high during the three days just before ovulation. A man’s sperm can live for 3-5 days in your reproductive organs—so if you have sex before you actually ovulate, the sperm can be in place and ready to fertilize the newly released egg! There are a few different methods you can use to identify your fertile window and increase your chances of pregnancy.
Day 15-24: Fertilization and Implantation
During this time frame, the ruptured follicle releases the progesterone hormone, which causes the uterine lining to thicken even more. Your fallopian tubes will help the egg travel down towards the uterus—and if it encounters a sperm and becomes fertilized, the egg could eventually attach itself to the uterine lining. This stage (called implantation) is when a pregnancy officially begins.
Day 24-28: Pregnant or Not?
If the egg isn’t fertilized, it will begin to break apart and your hormone levels will drop. This will cause your period to begin, and your cycle will begin again at Day 1. It’s this big hormone drop that can cause you to feel irritable and moody…ever heard of PMS (premenstrual syndrome)? That’s the cause.
If the egg is fertilized and implants in the uterus—congratulations, mama. You’re pregnant! While a missed period is often a good first indication that you’re pregnant, many women use a home pregnancy test to confirm a pregnancy. Home pregnancy tests detect the levels of hCG (human chorionic gonadotropin) in your urine—a hormone that is only present during pregnancy. The hCG levels increase with every day of pregnancy, which is why it’s recommended to wait until the first day of your missed period to take a test. While some tests are more sensitive and claim that they can detect a pregnancy before your missed period—you are likely to get more accurate results if you wait (as hard as it can be!). The earlier you take the test, the higher the chances are for a falsely negative test result.
We hope this refresher on the menstrual cycle is a useful tool for you and your partner in your journey to get pregnant. If you have questions, schedule some time with your provider to discuss your cycle and health history before trying to conceive. Best of luck!