In this Article

    How Long After Sex Does Pregnancy Occur?


    How Long After Sex Does Pregnancy Occur?

    Updated on 3 November 2023

    Pregnancy is a beautiful transitional journey that leads you to a new life as a mother. You birth a little version of yourself who fills your life with happiness. Arguably, pregnancy is one of the most rewarding and anticipated events of a woman’s life. Needless to say, it is a different experience for everyone and takes time to achieve.

    Let’s understand how long after sex does pregnancy occur. We shall begin from the start: sex. Although unprotected sex is where the process starts, it may not always lead to pregnancy. There are several checkpoints that your body has to go through to finally enter the stage of pregnancy. After sex, the sperm must fuse with the egg (the ovum) to produce a fertilised egg; this takes an entire series of events cascading into one another.

    Let’s now understand the science of conception

    Conception, also known as fertilization, is the process by which a sperm and an egg unite to form a zygote. This process begins with the deposition of sperm in the vagina and ends with the fusion of the sperm and the egg in the fallopian tube. For fertilization to occur, the sperm must be capable of propelling through the environment without being destroyed and must convert to a form that can penetrate the egg.

    Ovulation must occur, the egg must be picked up by the fallopian tube, and filmbriae and muscular contractions create a forward motion for the egg. The resulting zygote undergoes multiple cell divisions and develops into a blastocyst, which then implants in the uterus for growth. Defects in the fallopian tube can impair transport, increase the risk of a tubal pregnancy, and diminish egg quality over time.

    You may conceive as early as 30 minutes of sex!

    After sex, under normal circumstances, the sperm cells can fuse with an egg as soon as 30 minutes after entering the vagina aperture. An egg (ovum) is released into the fallopian tube every month by an alternate ovary, which typically happens on the 14th day of your last period. Once released, your egg remains viable to fuse with the sperm for the next 12 to 24 hours.

    Sperm cells are mobile and have the ability to swim toward the fallopian tube with a forward projection of 25 micrometres per second. Upon sex, the sperm cells travel toward the ovum to fuse and undergo the process of fertilisation in the fallopian tube (where the ovum remains for 12-24 hours). Typically, sperm cells can remain alive in your body for approximately 5 days after sex.

    The initiation of pregnancy is usually characterised by implantation when the fertilised egg gets implanted in the uterus. This implantation usually occurs at the time you would have got your period had you not become pregnant. This fertilised egg grows and develops into an embryo and finally a foetus. During this entire process, hormones play a vital role; any hormonal imbalance may affect the course of pregnancy.

    You may also like: How Long Does It Take To Get Pregnant?

    So, how long after sex does pregnancy occur?

    Given that your menstrual cycles are regular and you know when you are to ovulate, you have a fertile window of about 7 days in which you can get pregnant after sex. This means that if you have sex 5 days before expected ovulation, leading up to two days after it (day 9 to 16 since the first day of your last period), you can conceive (sperm-egg fusion) in as early as 30 minutes after sex!

    So, if you seem to have missed your period for more than a week, you can take a pregnancy test to confirm if you’re pregnant. This means that if you are planning to get pregnant, you should track your menstrual cycles and ovulation and work around accordingly.

    How do I know I’m pregnant?

    The endocrine system plays a significant role in pregnancy that might be indicated by diverse signs and symptoms. In case you’re pregnant, you may experience:

    1) A missed menstrual period

    If you're in your fertile years while being sexually active and you have regular periods, a delay in your menstruation cycle of more than a week or longer might indicate pregnancy. However, if you have been having an irregularity in your menstrual cycle physiologically, please consult your doctor.

    2) Tender/Swollen breasts

    The endocrine system fluctuates massively in the early months of pregnancy which might result in discomfort and tenderness in your breasts. The discomfort might arise due to sudden changes in your body and its response to hormonal changes; this discomfort should subside after a few weeks.

    3) Nausea with or without vomiting

    Morning sickness usually settles in one to two months into the pregnancy and can affect the expecting mother at any time of day or night. While it is difficult to understand the reason for nausea during pregnancy, hormones are most likely to blame.

    4) Fatigue

    Fatigue is a very common early symptom of pregnancy. It is difficult to pinpoint the cause of tiredness in the first trimester of pregnancy since the body is just getting adapted to the changing environment.

    5) Increased frequency of urination

    You may notice that you've been urinating more frequently than normal. During pregnancy, the volume of blood in your body rises. Since an embryo’s renal system is premature, the excretion is carried out through your kidneys, processing excess fluid that collects in your bladder.

    While the enlisted symptoms might indicate pregnancy, a pregnancy test kit might indicate the presence or absence of the same with almost 99 per cent accuracy. A pregnant woman releases the Human Gonadotropin Hormone (HCG), which is detected by home pregnancy test kits and is one of the most reliable methods to know for sure if you're pregnant. You may get a home pregnancy test kit at a pharmacy near you.

    When to consult the doctor?

    In the course of your pregnancy, your may consult your practitioner if you should take a prenatal vitamin with at least 400mcg of folic acid when you make an appointment. These vitamins are essential for the healthy development of your baby’s neural tube during early pregnancy. The brain and spine will emerge from the neural tube.

    An appointment with your healthcare practitioner prior to planning a pregnancy is a fantastic way to understand the journey toward pregnancy, as it’s one of the most special ones. If you take medicine for a chronic disease or have additional medical issues like diabetes, hypertension, or lupus, scheduling a preconception consultation is vital.

    Your physician will review any existing medical issues as well as your overall health prior to pregnancy at this session. This visit is designed to put you in the best possible position to start a new pregnancy.

    Final thoughts

    Knowing how long after sex does pregnancy occur is the first step towards your conception journey. It's important to track your ovulation, engage in unprotected sex during the fertile window, consume folic acid, avoid alcohol, smoking and drugs and manage any chronic conditions you may have to conceive a healthy baby.


    1. Allen J. Wilcox, M.D., Ph.D., Clarice R. Weinberg, Ph.D.and Donna D. Baird, Ph.D. (1995). Timing of Sexual Intercourse in Relation to Ovulation — Effects on the Probability of Conception, Survival of the Pregnancy, and Sex of the Baby. NEJM

    2. Konishi S, Saotome TT, Shimizu K, Oba MS, O'Connor KA. (2020). Coital Frequency and the Probability of Pregnancy in Couples Trying to Conceive Their First Child: A Prospective Cohort Study in Japan. NCBI

    3. Johnson, Sarah PhD; Marriott, Lorrae MSc; Zinaman, Michael MD. (2018). Increased Likelihood of Pregnancy from Sex on the Two Days Before Ovulation. Obstetrics & Gynecology


    Popular Articles 

    when would ectopic pregnancy symptoms start 

    8 weeks pregnant baby size mm 

    10 week pregnancy diet 

    8 weeks pregnant and bleeding when i wipe 


    Trending Articles 

    4 week pregnancy scan 

    4 week pregnancy baby size 

    4 week pregnancy sonography 

    7 week pregnancy diet 

    Is this helpful?



    Written by

    pepper potts

    Get baby's diet chart, and growth tips

    Download Mylo today!
    Download Mylo App


    our most recent articles

    Mylo Logo

    Start Exploring

    About Us

    At Mylo, we help young parents raise happy and healthy families with our innovative new-age solutions:

    • Mylo Care: Effective and science-backed personal care and wellness solutions for a joyful you.
    • Mylo Baby: Science-backed, gentle and effective personal care & hygiene range for your little one.
    • Mylo Community: Trusted and empathetic community of 10mn+ parents and experts.