Trying to get pregnant: Best time to have sex & how often

When in the menstrual cycle can you get pregnant?

Did you know that we’re actually only fertile for a maximum of six days in each menstrual cycle? This is called the fertile window, and it consists of the five days leading up to ovulation and ovulation day itself [1].

The length of the fertile window is determined by how long sperm can survive in the female reproductive system and how long the egg cell can survive once it’s released [2]. Sperm can survive for five days at most (under the right conditions), but the egg cell’s lifespan is shorter — it only lives for 12-24 hours after it’s released on ovulation day [3]. 

So, all in all, the fertile window lasts a total of six days, and you’ll have the best chance of getting pregnant if you’ve already had sex in the days right before ovulation so that sperm is waiting for the egg when it’s released on ovulation day.

What are the chances of getting pregnant on the fertile days?

It’s only during those six days that intercourse can lead to a pregnancy, so timing is important. In fact, chances even vary on the days in the fertile window itself. The days right at the start of the window, furthest from ovulation, have a lower chance of pregnancy, while the two days right before and on ovulation day give you the highest chance of conception [1]. 

However, even when timing sex perfectly, pregnancy isn’t a given. On the most fertile day in the menstrual cycle (the day before ovulation), the chance of getting pregnant from intercourse is roughly 30% [1].

Our chances of getting pregnant at any given time also depend on other factors. Age is one of the most important ones — it’s well-established that our fertility decreases with age. In general, we’re the most fertile in our twenties and early thirties, and then fertility rates decrease more rapidly in our mid-thirties and onward [4]. Other lifestyle factors that can affect fertility are diet, weight, stress, smoking, and excessive alcohol use [5]. It’s also important to remember that we’re all individuals, and some people will have an easier time getting pregnant than others.

How often should you have sex to get pregnant?

So, now that we’ve established when to have sex, you might be wondering how often you should have sex during those fertile days to have the best chances. Research has found that theoretically having sex every day or every other day during the fertile window leads to the highest probability of conceiving [2]. 

For some, it may feel like having sex this often — especially when also trying to time it during the most fertile days — creates a lot of pressure. This can make the experience less enjoyable or even downright stressful. While it can certainly feel like there’s only a small window of opportunity in each cycle, it’s also important to keep in mind that it only takes one sperm to fertilize an egg, while there are normally hundreds of millions of sperm in each ejaculation [6]. Most couples do become pregnant on their own within a year of trying [7]. So, try to not stress too much and enjoy each others’ company. If you need it, there’s also help available (more on that later).

Should you only have sex on the fertile days when trying to conceive?

It’s only during the fertile days that sex can lead to pregnancy. However, there’s no need to “save up” and only have sex during the fertile window if you want to do it more often. There’s even research to suggest that the quality of sperm may be affected when abstaining from sex — well, from ejaculating — for longer periods of time (more than 10 days for men with normal sperm quality) [8]. That said, not all sex needs to involve penetration. If you want to have sex outside the fertile days but aren’t feeling like having vaginal sex, there are lots of ways to be intimate, and masturbation is another option if one of you is feeling it and the other isn’t.

Again, it can feel like there’s a lot of pressure to perform for couples trying to conceive and sex should feel enjoyable for both parties. At the end of the day, it’s always up to you how often you want to have sex. If you’re not feeling like doing the deed that often, you can focus on the fertile window when you’re trying to conceive.

How to predict ovulation and the fertile days

Understanding when you ovulate is crucial to identifying those fertile days, but how do you actually go about predicting when you’re going to ovulate? Let’s go through some ways that you can understand when you’re ovulating during your menstrual cycle:

• Using ovulation tests: Ovulation tests (sometimes called LH tests) measure the amount of luteinizing hormone (LH) in urine. LH levels peak roughly 1-2 days before you ovulate, so a positive ovulation test is a good indication that you will ovulate soon [9]. However, it doesn’t confirm that ovulation has or will happen.
• Tracking cervical mucus: Your cervical mucus changes throughout your menstrual cycle and tracking it can help you find your most fertile days [10]. During the fertile window, the cervical mucus becomes clear and stretchy — with a consistency and color that resembles raw egg whites — and this helps the sperm swim and stay alive in the female reproductive system.
• Tracking your periods: For most, ovulation happens roughly two weeks before the next period starts [11]. Keeping track of your periods, for example with a cycle tracking app or using a regular calendar to mark the days, can be a helpful tool to find your fertile days during your menstrual cycle. However, there are now more sophisticated ways to learn the pattern of your cycle and it’s important to know that if your cycles are irregular, it can be tricky to predict ovulation this way since it will change from one cycle to the next, so you might want to combine it with other methods too.
• Measuring your basal body temperature (BBT): Your BBT, the body’s resting temperature, increases after ovulation due to an increase in progesterone levels [12]. By tracking your BBT throughout your cycle, you can understand when you usually ovulate and plan intercourse accordingly. However, it’s good to keep in mind that BBT tracking can only show ovulation after it’s already happened, i.e. after the fertile window has closed.
• Using Natural Cycles: When using NC° Plan Pregnancy, the FDA Cleared app can identify which days you’re most likely to be fertile in each cycle, helping you get pregnant faster. The algorithm behind the app learns your unique cycle by analyzing your biometric data — temperature data, period data, and optional ovulation tests — and your previous cycles to predict when you will ovulate, giving you a daily fertility status. Research shows that Natural Cycles finds fertile days more accurately than calendar-based methods [13]. 

What else can you do to increase your chances of getting pregnant?

Aside from timing sex during the fertile days, are there any other ways of increasing the chances of getting pregnant? Here, we’ve listed a few things you can do on your own:  

• Eat a balanced diet: While there’s limited evidence to support any specific dietary practices linked to higher fertility rates, eating a nutrient-rich diet with a good balance of carbs, protein, healthy fats, and fiber is good for promoting general health and may help the body ovulate regularly [5].
• Exercise regularly: Exercising regularly is good for our overall health, and moderate exercise has been suggested to help promote fertility [5]. However, excessive training while not eating enough food can have the opposite effect, so it’s important to build up your exercise routine and maintain a healthy balance with plenty of rest and proper nutrition.
• Maintain a healthy weight: Our weight can impact our hormones, and both obesity and being underweight have been linked with couples taking longer to get pregnant [6]. A very high or low weight can lead to cycle irregularities and lower ovulation rates, which, in turn, may make it more difficult to get pregnant [5, 14]. If you have questions about your weight when trying to get pregnant, it’s a good idea to speak with your healthcare provider.
• Take supplements: Women who are looking to get pregnant are generally recommended to take folic acid supplements (folic acid is important for the development of the brain and spine in early pregnancy) [15]. You can also consider taking prenatal vitamins that contain iron, vitamin D, and calcium — make sure you check with your healthcare provider what they recommend for you before taking any new supplements.
• Don’t smoke: Smoking has been linked with higher rates of infertility in both men and women [5], so it’s best to cut out smoking completely if you’re trying to conceive.
• Limit alcohol: An excessive use of alcohol may reduce your chances of conceiving [5]. While it’s fine to have a glass of wine or beer here and there, it’s recommended to limit your alcohol intake if you’re trying to get pregnant.
• Limit caffeine: When consumed in very large amounts (five cups per day or more), caffeine has been linked to it taking to conceive [5]. There’s most likely no need to skip your morning coffee or tea, but it can be a good idea to limit your caffeine intake if you usually consume a lot. 

Trying to get pregnant can feel daunting at times — with many dos and don’ts all over the internet (and maybe you’re even getting advice from people around you that you didn’t ask for!). It’s important to know that everyone’s journey to pregnancy looks different, and even if you do everything by the book, it’s normal that this process takes some time. We know it’s easier said than done, but try to be kind to yourself and not stress too much.

Are certain sex positions better for conceiving?

Speaking of enjoying the process, there’s no evidence to support that any specific sexual positions are better than others when it comes to trying to conceive (as long as you’re having vaginal intercourse) [6]. In short, as long as sperm enters the vagina, you’re good to go. 

While we’re busting myths, there’s also no need to lie down with your legs elevated after sex to increase your chances [6]. Sperm are fast swimmers and reach the cervical canal within a few seconds after ejaculation, so while it won’t hurt to lie down for a while afterward, you won’t hurt your chances if you move around or go to the bathroom. 

How long does it take to get pregnant?

Everyone has their own personal fertility journey, and how long it takes to get pregnant can vary greatly from one person to the next — for some, it takes only a couple of months while for others, it may take years. However, the majority of couples who don’t have any fertility issues get pregnant within a year of trying [7]. 

It’s common to feel impatient when pregnancy doesn’t happen right away, and for many, it can trigger fears that something is wrong. However, it’s completely normal that it can take some time to become pregnant, even when you’re fertile, healthy, and following all the guidance. 

When to talk to a doctor  

If you’re female and under 35 with no known fertility issues you will be generally recommended to try on your own for a year before seeking help from a medical professional [17]. If you’re older than 35, you should reach out to your healthcare professional after six months of trying, and if you’re above 40 or have medical conditions that may affect your fertility (like PCOS or endometriosis), you may want to seek help even sooner [18].

While the recommendations around when to reach out to a doctor largely depend on the woman’s age, trouble conceiving isn’t always down to the woman. In fact, the issue lies with the man in around one-third of cases [19]. One-third is due to the woman, and finally, in the last one-third of cases, the cause of the problem is unknown or due to a combination of fertility issues for both parties.

If you’re not succeeding in becoming pregnant despite trying for the recommended duration of time for your age, it’s important to talk to your healthcare provider so that you can get the right help. There are many options to help couples who struggle to get pregnant on their own, ranging from medication to trigger ovulation to IVF, so the key is to find the right option for you. 

Plan your pregnancy with Natural Cycles

There are so many aspects of fertility, but knowing when you ovulate is key to understanding when to time sexual intercourse to optimize your chances of getting pregnant. That’s where Natural Cycles comes in — NC° Plan Pregnancy takes the guesswork out of the equation by helping you identify which days you have the highest chances to conceive, giving you individualized insights into your fertility. 

During your pregnancy, you can track your baby’s development and your body’s changes with NC° Follow Pregnancy, and then seamlessly switch to NC° Postpartum once you give birth for additional support while you recover. Why not see if Natural Cycles could be right for you today?