"How fertile am I?" A look at what days may help with getting pregnant

Medically reviewed by Neka Miller, PhD on July 15, 2021. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

We learn about the miracle of life in health or sex education classes, and the whole concept seems simple enough. The sperm cell meets the egg cell, and after nine months, a baby gets born.

In reality, things are a bit more complex and nuanced than that. Fertility has numerous different facets, and one of the most important factors determining female fertility is timing, often referred to as the fertile window. While many people wonder how fertile they are, another pertinent question is when. Read on to learn more about your fertility, when you can get pregnant, and if you should consider FSH testing.

Ovulation and Your Menstrual Cycle

You can ostensibly get pregnant as soon as you begin your menstrual cycle. Your menstrual cycle occurs every month and is a means of preparing your body for pregnancy. The process is controlled by hormones — primarily estrogen and progesterone — which help to regulate the process. During the menstrual cycle, the ovaries also release a mature egg, meaning that it is capable of being fertilized by a sperm cell.

Along with the release of an egg, the hormones cause the lining of the uterus to become thicker and spongier, which accommodates a fertile egg, giving it the perfect spot to stick to and begin a pregnancy. If the egg does not get fertilized at this time, your body gets rid of this extra uterine lining, resulting in your typical period.

Ovulation refers to the process when your ovaries release an egg each month. In those with regular menstrual cycles, ovulation occurs about two weeks before the start of their period. For those with irregular cycles, ovulation can start anywhere from 12 to 16 days before the start of their next period. Furthermore, the time and actual duration of ovulation will vary as you get older.

This is why tracking your menstruation and ovulation is a great place to start when planning for a pregnancy. Everyone with ovaries will have their period at different times of the month. Understanding your fertile window and exactly when you are ovulating gives you a better shot at actually getting pregnant.

Your Fertility Window

If you’re wondering how to increase fertility, it is important to understand your fertility window. Your increased fertility window or fertile days refer to when you are at your most fertile and thus more likely to get pregnant. This window coincides with your ovulation.

The exact window will vary from person to person, but it generally lasts about six days. That comprises the actual day when you ovulate (a mature egg will stay fertile for about 12 to 24 hours after being released from the ovaries) and the longevity of a sperm cell. Sperm cells can live in your uterus and fallopian tubes for about five to six days.

If you suspect any chances of infertility, notice common signs of infertility in women, or if you're having difficulty getting pregnant, you may want to consider fertility testing. While fertility testing can be done with the help of a fertility specialist, at-home fertility tests are also available to check the levels of essential hormones that play a part in your menstruation and fertility. Whichever test you choose, you can then determine if fertility treatment is the next step for you.

Knowing When You’re Ovulating

Tracking your menstrual cycle manually with a calendar or through a tracking app or website is a great way to monitor your cycle and determine when you are ovulating and maintain fertility awareness. This is largely predictive, but if you have a regular cycle, it gets easier to predict your period each month.

Home testing kits, such as a fertility or ovulation predictor kit, can take much of the guesswork out of the process. Some testing kits detect the presence of luteinizing hormone (LH). About 24 to 36 hours prior to ovulation, your LH levels naturally increase. The hormone signals the release of an egg from either of your ovaries. A positive test means an increase in the hormone, suggesting that ovulation is imminent. It’s best to have sexual intercourse about three days after a positive test result to increase the odds of pregnancy.

Ovulation can also cause physiological changes, like a slight increase in basal body temperature, though this can be difficult to notice or track. Some people track ovulation by monitoring their cervical mucus. A few days before ovulation, cervical secretions are thin, clear, slippery, and stretchy. This is designed to help sperm cells travel to the egg. The day after ovulation occurs, cervical mucus becomes thicker in consistency and cloudier in appearance.

Can You Still Get Pregnant Outside of Your Fertility Window?

While your fertile days are when you have the highest chance of getting pregnant, you can technically get pregnant at almost any point in your entire menstrual cycle.

While On Your Period

Menstruation lasts about three to seven days on average. During this time, your body is shedding the blood, tissues, and nutrients comprising the uterine lining, as well as the unfertilized egg. For most people with ovaries, there’s very little chance of getting pregnant at this time. The sperm cells basically won’t have any eggs to even fertilize.

However, it’s not unheard of for some people to get pregnant at this time, particularly if you ovulate earlier than others. The chance just happens to be extremely low, but having sex on your period is not detrimental.

Right After Your Period

Around day seven of your cycle, after your period has ended, your fertility should be returning again. This does not necessarily mean that your ovaries have released an egg yet, but it does mean that it’s on the way. Remember, sperm can live upwards of five days in the uterus and fallopian tubes, and if you ovulate earlier than usual, it’s a good possibility that those sperm will find their way to the released egg.

After Ovulation

Known as the luteal phase, the post-ovulation stage lasts about 12 to 16 days. Progesterone levels rise, signaling to the ovaries that they don’t need to release any more eggs, and cervical mucus gets sparse to keep sperm from entering the uterus.

Chances of getting pregnant immediately after ovulation are fairly low, though not as low as during your period. Remember that the egg is only fertile for about 24 hours when it’s been released from an ovary. After that, the egg begins to degenerate.

Fertility As You Age

You have a set number of eggs. At birth, you are born with 1 to 2 million eggs, and by the time you reach your first period, that number goes down to about 300,000. That is as many eggs as you will ever have. As you go through your menstrual cycle every month, you get rid of one egg, and not all of those eggs are necessarily healthy or viable.

You are the most likely to conceive in your early 20s, during which about 90 percent of your eggs are chromosomally normal. For the average woman, peak fertility occurs around the age of 24 with a 96 percent chance of conceiving in a year. From your mid-to-late 20s, your chances are still high at about an 86 percent chance of conceiving when trying for a year.

While research does still see a decline when women hit their 30s, the chances are still fairly high. Chances of conceiving gradually go down until you hit menopause, which marks the end of a person’s ability to get pregnant. You officially hit menopause when you haven’t had your period for a year and if your follicle-stimulating hormone (FSH) levels are consistently elevated.

If you have been trying to get pregnant for a year with no luck and are curious why getting pregnant is so difficult, consider talking to a fertility specialist and potentially taking a fertility test for women. There are many factors involved with getting pregnant, from timing to stress to basic health.

Related content

Potential signs and symptoms of diminished ovarian reserve

Why some women have a low egg count

What are the signs of high fertility in a woman?

Why getting pregnant can be difficult

References

1. Pregnancy: Ovulation, Conception & Getting Pregnant. Cleveland Clinic. URL. Accessed July 15, 2021.

2. Getting pregnant. Mayo Clinic. URL. Accessed July 15, 2021.

3. Normal Menstruation. Cleveland Clinic. URL. Accessed July 15, 2021.

4. Female Reproductive System. Cleveland Clinic. URL. Accessed July 15, 2021.

5. Follicle-Stimulating Hormone (FSH) Levels Test. MedlinePlus. URL. Accessed July 15, 2021.