12 weeks pregnant: Your guide to this week of your first trimester

    Updated 04 July 2023 |
    Published 24 February 2019
    Fact Checked
    Reviewed by Dr. Nazaneen Homaifar, Obstetrician and gynecologist, Inova Health System, Washington, DC, US
    Written by Christina Quaine
    Edited by Sarah Biddlecombe
    Flo Fact-Checking Standards

    Every piece of content at Flo Health adheres to the highest editorial standards for language, style, and medical accuracy. To learn what we do to deliver the best health and lifestyle insights to you, check out our content review principles.

    From developing a pregnancy bump to seeing your baby’s heart activity for the first time, here’s the lowdown on being 12 weeks pregnant.

    At 12 weeks pregnant, you’re now nearing the end of your first trimester. Your baby is developing at an incredible rate, and you might be feeling more human if you’ve been finding those pregnancy symptoms challenging. Let’s take a closer look at what else is happening this week, with some advice from a Flo expert.

    Your baby at 12 weeks pregnant

    Hand movements 

    Your baby is starting to move their little hands, although you won’t feel those movements just yet, as they’re still too small. But their fingernails are also sprouting, and they’ll have a fully grown set of nails by 33 weeks.

    Their liver is developing

    Did you know that all of your baby’s internal organs are created by 12 weeks? One organ that’s developing right now is their liver. This hard-working organ has a mind-boggling 500+ functions, and this week it will start producing bile, which helps with your baby’s digestion.

    How big is a baby at 12 weeks pregnant?

    Length (crown to rump): Around 5.4 cm or 2.1 in.

    Weight: Around 58g or 2 oz.

    Size: Equivalent to a lime.

    All measurements are approximate and vary within the normal range.

    Your body at 12 weeks pregnant

    Is that a pregnant belly you see?  

    This could be the week that you finally start to show your pregnant belly. “At 12 weeks, you could definitely be showing a bit. Your uterus has grown up and out of your pelvis, your waist is expanding, and you might be finding it harder to do up your regular pants,” explains Dr. Jenna Flanagan, obstetrician and gynecologist at Beth Israel Deaconess Medical Center, Massachusetts, US. “If you’ve been pregnant before, or you’re expecting more than one baby, you might show earlier.” 

    As your belly starts to expand, it makes sense that your skin will also begin to stretch to accommodate your growing baby. This could eventually lead to the development of stretch marks, although these are particularly common later on in your pregnancy, when you reach your third trimester. 

    While physical changes such as stretch marks highlight how incredible your body is during pregnancy, they can also be difficult to adjust to. If you have any concerns or questions, you can always reach out to your doctor or seek support from your loved ones. And on a positive note, remember that stretch marks are harmless and won’t affect your pregnancy.

    Mood swings

    Feel like you’re on an emotional roller coaster right now? Mood swings in pregnancy are common, especially in early pregnancy, when your hormone levels are changing. Added into the mix is the fact that you might also have worries about your baby and your new life as a parent. A degree of these feelings can be normal in pregnancy (and you’re certainly not alone in having them!). However, if you find that they’re affecting your day-to-day life, or you’re worried about your mood and mental health in pregnancy, then be sure to speak to your doctor.   

    Your questions answered

    How might I be feeling at 12 weeks pregnant?

    If you’ve been struggling through troublesome pregnancy symptoms, you might just be feeling a little better by 12 weeks. “For most people, nausea, vomiting, food aversion, and bloating are getting a little bit better,” says Dr. Flanagan. “Nausea and vomiting tend to get better about now because your levels of the pregnancy hormone human chorionic gonadotropin have peaked, and they sometimes drop a little bit, too. Then the placenta is taking over to support your baby — all of which can make you feel a bit better.”

    You might also be feeling some relief at 12 weeks pregnant, as your risk of having a miscarriage falls considerably toward the end of your first trimester. This is an important milestone to reach, and you may choose to start telling more people about your pregnancy from this point onward.

    Can I feel my baby at 12 weeks?

    You’ll usually start to feel your baby moving between around 16 and 24 weeks pregnant, so you still have a few weeks to wait (but hang in there — there’s not too long to go!). “If you’ve been pregnant before, you might feel the movement at the earlier end of that window,” adds Dr. Flanagan. “If you have an anterior placenta — when your placenta grows at the front of your uterus — you might first feel movement towards the later end of that window.” This can be frustrating, but it’s common during pregnancy. It simply means your placenta is acting like a cushion between your belly and your baby, and you might feel more movement on the sides of your abdomen instead.

    Is 12 weeks pregnant the same as 3 months?

    It sure is! Twelve weeks is around the three-month mark of your pregnancy. 

    Want to know more?

    Download the Flo app for tailored insights throughout your pregnancy

    Your 12 weeks pregnant checklist 

    Check your vitamin A levels

    Healthy eating in pregnancy is really important, for both you and your baby. One thing to consider when planning your pregnancy diet is to make sure you’re getting the right levels of vitamin A. This nutrient is crucial for helping your baby to develop healthy vision, skin, and bones. Good sources of vitamin A in pregnancy include carrots, green leafy vegetables, and sweet potatoes, so be sure to add these items to your grocery cart. A pregnant adult’s recommended amount of vitamin A is 770 mcg. To give you an idea of what’s in your food, half a cup of raw carrots contains 459 mcg

    However, it’s also important to note that consuming too much vitamin A could be harmful during your pregnancy (confusing, right?). With this in mind, it’s always good to speak to your doctor before taking any new supplements or making changes to your diet.

    When to see your doctor at 12 weeks pregnant

    You will probably have an appointment around the end of your first trimester to check how you and your baby are doing. During this appointment, you can expect your doctor to check: 

    When you’re around 12 to 14 weeks pregnant, you and your doctor should also be able to see your baby’s heart activity using a small device called a Doppler. Exciting times! 

    Plus, don’t forget that you don’t need to wait until your appointments if you have any concerns or questions about your pregnancy. However, at 12 weeks pregnant you should contact your doctor immediately if you experience: 

    This isn’t an exhaustive list and just an example of some of the changes you should look out for. Some of these can be a sign of miscarriage or other health complications, so it’s essential that you speak to your doctor about the best next step for you. And if you’re ever worried about any other symptoms you experience during pregnancy, then don’t hesitate to reach out to your healthcare provider. 

    12 weeks pregnant: The takeaway

    You’re almost through your first trimester and getting ready to head into your second, which can be an exciting milestone. This week you might start to show a baby bump, and you might even be able to see your baby’s heart activity for the first time, too!


    “Anterior Placenta.” Cleveland Clinic, my.clevelandclinic.org/health/diseases/23306-anterior-placenta. Accessed 26 May 2023.

    Artal-Mittelmark, Raul. “Stages of Development of the Fetus.” MSD Manual Consumer Version, Sep. 2022, www.msdmanuals.com/en-gb/home/women-s-health-issues/normal-pregnancy/stages-of-development-of-the-fetus.

    “Bleeding during Pregnancy.” The American College of Obstetricians and Gynecologists, May 2021, www.acog.org/womens-health/faqs/bleeding-during-pregnancy

    Curran, Mark A. “Fetal Development.” Perinatology.com, perinatology.com/Reference/Fetal%20development.htm. Accessed 26 May 2023

    “Fetal Development.” Cleveland Clinic, my.clevelandclinic.org/health/articles/7247-fetal-development-stages-of-growth. Accessed 26 May 2023.

    “Feelings, Relationships and Pregnancy.” NHS, www.nhs.uk/pregnancy/support/feelings-and-relationships/. Accessed 26 May 2023.

    “Fetal Development: What Happens during the 1st Trimester?” Mayo Clinic, 3 June 2022, www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/prenatal-care/art-20045302.

    “Fetal Development: What Happens during the 3rd Trimester?” Mayo Clinic, 3 June 2022, www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/fetal-development/art-20045997.

    Friel, Lara A. “Fevers during Pregnancy.” MSD Manual Consumer Version, Oct. 2021, www.msdmanuals.com/home/women-s-health-issues/pregnancy-complicated-by-disease/fevers-during-pregnancy.

    “How Your Fetus Grows during Pregnancy.” The American College of Obstetricians and Gynecologists, Aug. 2020, www.acog.org/womens-health/faqs/how-your-fetus-grows-during-pregnancy

    Johnson, Payton, et al. “Functional Bowel Disorders in Pregnancy: Effect on Quality of Life, Evaluation and Management.” Acta Obstetricia et Gynecologica Scandinavica, vol. 93, no. 9, Sep. 2014, pp. 874–79, https://doi.org/10.1111/aogs.12434

    “Liver: Anatomy and Functions.” Johns Hopkins Medicine, Nov. 2019, www.hopkinsmedicine.org/health/conditions-and-diseases/liver-anatomy-and-functions.

    “Methods for Estimating the Due Date.” The American College of Obstetricians and Gynecologists, May 2017, www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2017/05/methods-for-estimating-the-due-date

    “Morning Sickness: Nausea and Vomiting of Pregnancy.” The American College of Obstetricians and Gynecologists, May 2020, www.acog.org/womens-health/faqs/morning-sickness-nausea-and-vomiting-of-pregnancy.

    “Nutrition during Pregnancy.” The American College of Obstetricians and Gynecologists, May 2023, www.acog.org/womens-health/faqs/nutrition-during-pregnancy

    “Placenta.” Cleveland Clinic, my.clevelandclinic.org/health/body/22337-placenta. Accessed 26 May 2023.

    “Prenatal Care: 1st Trimester Visits.” Mayo Clinic, 6 Aug. 2022, www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/prenatal-care/art-20044882.

    “Quickening in Pregnancy: First Movements & What to Expect.” Cleveland Clinic, my.clevelandclinic.org/health/symptoms/22829-quickening-in-pregnancy. Accessed 26 May 2023.

    Sisco, Emily. “5 Ways to Prepare before Starting a Family.” Mayo Clinic Health System, 21 Mar. 2019, www.mayoclinichealthsystem.org/hometown-health/speaking-of-health/5-ways-to-prepare-before-starting-a-family

    Sparling, J. W., et al. “Fetal and Neonatal Hand Movement.” Physical Therapy, vol. 79, no. 1, Jan. 1999, pp. 24–39, https://doi.org/10.1093/ptj/79.1.24.

    “Stretch Marks.” Mayo Clinic, 12 Jan. 2023, www.mayoclinic.org/diseases-conditions/stretch-marks/symptoms-causes/syc-20351139.

    “Stretch Marks in Pregnancy.” NHS, www.nhs.uk/pregnancy/related-conditions/common-symptoms/stretch-marks. Accessed 26 May 2023.

    “Symptoms of Pregnancy: What Happens First.” Mayo Clinic, 3 Dec. 2021, www.mayoclinic.org/healthy-lifestyle/getting-pregnant/in-depth/symptoms-of-pregnancy/art-20043853.

    “Urgent Maternal Warning Signs.” Centers for Disease Control and Prevention, 27 Feb. 2023, www.cdc.gov/hearher/maternal-warning-signs/index.html.

    “Vaginal Discharge in Pregnancy.” NHS, www.nhs.uk/pregnancy/related-conditions/common-symptoms/vaginal-discharge/. Accessed 14 June 2023.

    “Vitamin A and Carotenoids.” National Institutes of Health: Office of Dietary Supplements, 15 June 2022, ods.od.nih.gov/factsheets/VitaminA-HealthProfessional/

    “What Happens during Prenatal Visits?” Eunice Kennedy Shriver National Institute of Child Health and Human Development, www.nichd.nih.gov/health/topics/preconceptioncare/conditioninfo/prenatal-visits. Accessed 26 May 2023.

    “Week by Week Guide to Pregnancy.” NHS, www.nhs.uk/start4life/pregnancy/week-by-week/1st-trimester/week-4/. Accessed 26 May 2023.

    “Your Baby’s Movements.” NHS, www.nhs.uk/pregnancy/keeping-well/your-babys-movements/. Accessed 4 July 2023.

    History of updates

    Current version (04 July 2023)

    Reviewed by Dr. Nazaneen Homaifar, Obstetrician and gynecologist, Inova Health System, Washington, DC, US
    Written by Christina Quaine
    Edited by Sarah Biddlecombe

    Published (24 February 2019)

    In this article

      Try Flo today

      Sign up for our newsletter

      Our latest articles and news straight to your inbox.

      Thanks for signing up

      We're testing right now so not collecting email addresses, but hoping to add this feature very soon.