How long does it take to get pregnant after sex?

You probably know that having unprotected sex can lead to getting pregnant. But how long does it take to get pregnant after sex? In this article, we’ll unpack this question and discuss how to improve your chances of getting pregnant if you’re trying to conceive.

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Implantation can take up to two weeks to occur after having sex without using a birth control method (Jarvis, 2016). This might sound like a long time to you, so let’s define a few terms and explore the steps from sexual intercourse to implantation (pregnancy) in a little more detail:

Step 1: You’re in your “fertile window”

Your fertile window is the period of time during the month when you can actually conceive; this is roughly an 8-day window. It starts about a week before ovulation (when your ovaries release an egg, and it’s available to be fertilized for up to two days). 

Sperm cells can survive in the female reproductive tract for almost a week, which allows sperm from sex you have a week before ovulation to still be able to swim up to meet the egg once it’s released (Ecochard, 2015). 

Step 2: You have unprotected sex

This allows the sperm to get near the egg. “Unprotected” means having penis-in-vagina sex (or even penis-vagina contact) without using birth control or without reliably using birth control. That means, for example, if you take your pill most of the time but missed it for a few days or are a couple of weeks late in getting your birth control shot, you’re technically having unprotected sex and can get pregnant. 

Step 3: Fertilization occurs

Fertilization is when the sperm meets the egg and fertilizes it, turning it into an embryo. It can happen as soon as a few hours after sex (if you’re ovulating at the time and the sperm are real go-getters) or up to a week after having sex (if you had sex before actually ovulating) (Pairman, 2010).

Step 4: Implantation occurs

Implantation is when the fertilized egg moves to the wall of the uterus and attaches itself, which is the scientific definition of pregnancy. This can take up to a week after fertilization happens (Jarvis, 2016). Within a few weeks, your pregnancy hormone levels rise enough that you may feel some early pregnancy symptoms like fatigue or cramping.

This all means that, in total, you can get pregnant (i.e., the embryo implants in your uterus) anywhere from within hours of having sex to two weeks after having sex.

Age does seem to play a role in how long it takes to get pregnant. Over age 35, the rate of conception for women begins to decline.

Interestingly, one study showed that the length of the monthly fertile window itself didn’t change for women below age 40 but did show that the overall chances of getting pregnant do decrease above age 35. Fertility for men is less affected by age than in women but does decline by the late 30s (Dunson, 2002).

You can take an at-home pregnancy test as soon as you want, but it won’t show a positive result until the embryo is implanted in your uterine wall, which could be a few weeks after having sex. 

The more sensitive pregnancy tests can show a pregnancy the day you miss your period, but less sensitive ones are more accurate at around 10 days after your missed period (Anderson, 2022; Cole, 2005). 

Home pregnancy tests work by measuring the amount of “pregnancy hormone,” or human chorionic gonadotropin (hCG), in your urine. Your body begins to produce hCG after implantation, so when to take a pregnancy test can vary from person to person since both implantation times and normal hCG levels can vary widely (Betz, 2021; Oliver, 2021). 

That means that some pregnancies may have detectable hCG levels several days earlier than others. It also means that if you take your test too early, you might get a false negative result just because your hCG levels haven’t had the chance to increase yet.

Pregnancy hormones also show up in your blood and can be detected sooner than in a urine test. Certain blood (serum) tests can detect a pregnancy within 48 hours of egg fertilization, but these tests have to be done in a lab or doctor’s office (Anderson, 2022).

If you’re trying to conceive, there are a few things you can try to increase your chances of getting pregnant:

Have sex every day in your fertile window

Many people wonder how often they should have sex to get pregnant. 

Having sex frequently during your fertile window may help maximize your chances of becoming pregnant. It’s a common misconception that abstaining from sex improves sperm quality. 

However, if having sex that often feels stressful, don’t worry—your chances of getting pregnant are nearly as good if you just have sex 2–3 times per week during your fertile period (ASRM, 2022).

Optimize your health

You can help ensure that your body is ready to take on the demands of pregnancy—and increase your fertility—by keeping healthy and nourishing your reproductive health. 

This means eating a nutritious diet (like the Mediterranean diet, which positively impacts fertility) and maintaining a healthy weight (that means having not too much but not too little body fat) (Skoracka, 2021; Walker, 2021).

Limit smoking and caffeine

Cigarette smoking and high amounts of caffeine are associated with reduced fertility in women. Both can be difficult to quit, but fortunately, just reducing your cigarette and caffeine consumption can positively impact your ability to conceive (Sharma, 2013). 

Try to decrease stress

Female fertility is driven in part by a delicate balance of hormones, and stress can greatly impact this (Palomba, 2018). 

While low amounts of stress or occasional stress can be normal and healthy, too much can cause you to frequently release stress hormones, and some of these can decrease your chances of conception (Sharma, 2013). 

Try stress-reduction strategies like therapy (especially cognitive behavioral therapy), mindfulness meditation, and asking for support with work and home demands.

Many people who want to get pregnant don’t actually conceive right away—and that’s completely normal. Most couples conceive within the first six months of trying. 

However, at a certain point, it’s a good idea to see a provider to look for signs of infertility if you’re trying to get pregnant but not having any luck.

• If you’re below age 35, you may be having fertility problems if you don’t become pregnant after 12 months of regular unprotected sex (ASRM, 2022). That’s the point when your provider may recommend fertility testing. If you’ve been trying to get pregnant for over six months, it’s a good idea to talk over your lifestyle and health history with your provider to see if there is anything you and your partner can address early on.

• If you’re over the age of 35, infertility can be diagnosed after six months of having difficulty conceiving—that’s because pregnancy rates do begin to dip in this age group, so fertility testing to check for things like low sperm count or a female hormone imbalance may be recommended at this earlier point in time (ASRM, 2022). 

There may be simple fixes that can help boost your chances of conception—like using ovulation testing to time sexual intercourse—or there may be a more significant medical issue to address.

Fortunately, there are fertility treatments and reproductive technologies like in vitro fertilization (IVF) or intrauterine insemination (IUI) that may be able to help pregnancy occur.

If you’re interested in learning more about your fertility but aren’t ready to see a provider, fertility tests for women are available over the counter. While they can’t tell you for sure whether you can get pregnant or not, they can give a wealth of helpful information that can be a part of the larger fertility puzzle.

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Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

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Current version

May 27, 2022

Written by

Nancy LaChance, BSN, RN

Fact checked by

Steve Silvestro, MD

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About the medical reviewer

Steve Silvestro, MD, Ro

Dr. Steve Silvestro is a board-certified pediatrician and Associate Director, Clinical Content & Education at Ro.