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12 Weeks Pregnant: Week-by-Week Guide

12 Weeks Pregnant: Week-by-Week Guide

Congratulations! You’re 12 weeks pregnant and in the home stretch of your first trimester. At this stage of your journey, new developments are quickly unfolding. Check out this week-by-week guide to find out what’s in store for your baby and your body in week 12 of pregnancy.


  • How far along is 12 weeks pregnant? First trimester
  • How many weeks of pregnancy are left? 28 weeks
  • How many months is 12 weeks pregnant? You’re in your third month. 

With week 11 of your pregnancy complete, you’re on week 12. Enjoy it, as week 13 is on the horizon! 

One of the most exciting things about pregnancy is how many changes you’ll experience with your little one over the span of just seven days! Here are some tips and tricks to keep on top of all that’s happening.

Your baby at 12 weeks pregnant

What’s happening in there

  • Your baby at 12 weeks is the size of a lime.
  • You’re officially in the last week of your first trimester.
  • The countdown continues: You’ve got 28 weeks to go!

12 weeks: baby development

  • All systems go: Most of your baby’s internal systems are formed by week 12. The kidneys are functioning and can turn any amniotic fluid consumed into urine. That little abdomen is now large enough to hold the intestines, and the digestive muscles are contracting in preparation for being able to eat and digest after birth. The liver is producing blood cells now too, helping to really accelerate development.
  • Get ready to make some noise: At week 12, your baby’s vocal cords are developing, preparing for giggles, gurgles, and the inevitable crying when you finally meet.
  • Prepping for that close-up: By week 12, your baby’s profile will be visible on a sonogram, with all the changes to their face discernible.
  • The internal computer has started up: The corpus callosum is developing. This is a bundle of 200 million axons, or nerve fibers, that coordinates motor, sensory, and cognitive functions between the right and left sides of the brain.

What’s going on with your 12-week embryo?

Well, your baby is growing … and is actually not in the embryonic stage anymore. At eight weeks from fertilization, the embryo has transitioned to the fetus stage. Time is going fast!

What should I be feeling at 12 weeks pregnant?

  • You’re going to feel the love the first time you hear your baby’s heartbeat. It’s usually audible during checkups at the 12th week mark.
  • You will feel bloated as your intestines are unceremoniously moved out of the way by your hungry little baby, coupled with the effects of progesterone. This pregnancy hormone is responsible for slowing down your digestive system, giving your blood more time to absorb nutrients and pass them through to your baby. 
  • You’re going to be tired a lot more. You are now working 24/7 to not only fuel your baby’s growth, but also to produce the placenta. It’s a small miracle, but anytime you feel you’re exhausted, take a little “you time” while you still can!
  • The constant urge to pee should hopefully have subsided by week 12.

How big is my baby at 12 weeks in the womb? 

12 Weeks Pregnant

Baby Weight 0.5 ounces
Baby Length 2–2.5 inches
Baby Size

Comparable to a lime or a plum


Week 12 pregnancy symptoms

During week 12 of pregnancy, your body is changing quickly. As your baby grows, you will too, and there are certain pregnancy symptoms you may experience at this time.

8 common 12 weeks pregnant symptoms and pain

  1. Burping, bloating, and flatulence are part of the side effects of pregnancy hormones that relax the digestive tract. Avoid beans, fizzy sodas, candy, and fried foods.
  2. Hooray, you’re not feeling sick! Instead, welcome to progesterone’s new trick—dizzy spells. This pregnancy hormone can cause your blood vessels to widen to increase blood flow to your baby, but it slows its return to you, causing lower blood pressure and light-headedness.
  3. You may be producing excessive saliva. It’s an odd symptom, but rather than drooling, try chewing gum!
  4. Your sex drive can drop considerably. It’s completely understandable at this point as your body is playing so many tricks on you both physically and emotionally.
  5. At 12 weeks pregnant, headaches, driven by—you guessed it—hormones, are common. 
  6. You may start to experience what is called round ligament pain. This pregnancy symptom, which feels like sharp jabbing discomfort in your abdomen or hip area, is caused by the extra pressure put on your ligaments as your belly expands and stretches. Certain exercises may help. Just be sure to get an OK from your doctor first.
  7. Vaginal discharge will continue throughout your pregnancy.
  8. Your skin may be changing. You may notice the “mask of pregnancy,” or chloasma, appear in brownish patches on your face and neck. These will usually lighten or disappear after your baby is born.

Will I be showing at 12 weeks pregnant?

Women at 12 weeks pregnant may be showing, especially if they’ve had previous pregnancies or are carrying multiples. Is this your first baby? Your belly might be sporting that telltale bump, but you may have to wait a little longer. The pregnancy belly pop will be here soon enough.

3 tips for week 12 for a healthy and safe pregnancy

Being 12 weeks pregnant is an important time for you and your baby. Here are some tips on how to adjust to this new stage to keep you and your baby safe.

  • Fuel their mind: Now that your baby’s brain and nerves are developing rapidly, you need to fuel that growth with the right foods. Combine a healthy diet with prenatal vitamins that include DHA (docosahexaenoic acid) to nourish your baby’s fine motor development and vision.
  • Slow and steady wins the race: Your joints are probably loosening up from a hormone called relaxin, which will eventually aid the opening of your cervix. For now, it can also loosen ligaments throughout your body, making you more prone to injury. So take things slow and steady, whether you’re working out or carrying groceries.
  • Don't let the flu get you down: Be sure to get a flu shot; the CDC recommends vaccination for all moms-to-be.

Week 12 pregnancy checklist

Knowing what to do week-by-week can help you feel prepared and alleviate stress. Add these new items to your to-do list this week. You’ve got this, mama!

Week 12 Pregnancy To-Do’s Complete

Learn what food to avoid

   Learn what food to avoid is complete

If you haven’t already, quit alcohol

   If you haven’t already, quit alcohol is complete

Choose some looser fitting clothes

   Choose some looser fitting clothes is complete

Learn more about your pregnancy, including pregnancy planning and pregnancy nutrition, to feel prepared to continue this magical adventure. You’re armed with the facts and know what to do, so now you can take time to connect with the little one growing inside you.

With week 11 in the rearview mirror and week 12 going strong, look to the future and what's coming up in week 13!

Join Enfamil Family Beginnings

It’s your 12th week of pregnancy, and you and your baby are experiencing exciting changes every day. Prepare for your new arrival with help from Enfamil Family Beginnings. It’s the perfect resource for new and expecting moms. Save on Enfamil products, track your bump and baby’s growth, and get helpful articles each week relevant to your journey. Join now for up to $400 in free gifts.