First Trimester of Pregnancy: What to Expect for Weeks 1-13

By Red Rock Fertility     Posted September 17, 2020     In

First Trimester of Pregnancy: What to Expect for Weeks 1-13 Header

Every trimester has its own traits, from how your baby is developing to symptoms you are feeling. The first trimester of pregnancy is one filled with rapid change and new experiences. If you are an expecting parent, use this guide to learn what to expect in the first 13 weeks of pregnancy!

 

An Overview of Your First Trimester of Pregnancy

 

During the first trimester, you’re getting used to the idea of being pregnant, and pregnancy symptoms week-by-week can vary a lot! With pregnancy symptoms like morning sickness and exhaustion, your body will be feeling many internal changes during this early pregnancy phase.

Throughout this time, you may experience first trimester pregnancy symptoms such as:

  • Acne
  • Bloating
  • Breast changes
  • Cervical changes
  • Cervical mucus
  • Constipation
  • Cramps
  • Dizziness
  • Extra saliva
  • Fatigue
  • Food preferences
  • Frequent urination
  • Gas
  • Headache
  • Heightened sense of smell
  • Increase in energy
  • Increased sex drive
  • Leg cramps
  • Lower back pain
  • Mood swings
  • Morning sickness
  • Nasal congestion
  • Nausea
  • Pelvic ache
  • Round ligament pain
  • Skin darkening
  • Vaginal bleeding
  • Vaginal discharge
  • Visible veins
  • Weird dreams

Not only do you have pregnancy symptoms to take into consideration, there are a lot of emotions that are felt, from excitement for your growing family to nervousness about parenthood. With the right resources and a good understanding of these first 13 weeks, you’ll feel more confident as you start your pregnancy journey.

 

The First Trimester Weeks

 

Week 1 of Pregnancy

First Trimester Week 1: Menstruation

According to most health care providers, your first week of pregnancy means you’re on your period and actually not pregnant yet. You won’t actually conceive your baby until week two or three, depending on the length of your cycle. If you’ve just found out you’re expecting, you might think this is your first week of pregnancy, but you’re probably around 4 weeks pregnant!

At this point, your pregnancy symptoms are simply your typical period symptoms:

  • Vaginal bleeding
  • Lower back pain and cramps
  • Bloating
  • Mood swings
  • Headache

 

Week 2 of Pregnancy

First Trimester Week 2: Ovulation

Similar to week 1 of pregnancy, you are likely not yet pregnant. However, this is the point when you may be ovulating and ready to conceive. In the second week of pregnancy, symptoms of ovulation can clue you in on the best time to have sex and hopefully conceive a baby.

You’re probably ovulating if you notice these signs at week 2 of pregnancy:

  • “Egg white” cervical mucus
  • Better sense of smell
  • Breast soreness or tenderness
  • Pelvic ache
  • Light spotting
  • Increased sex drive
  • Cervical changes

 

Week 3 of Pregnancy

First Trimester Week 3: A few cells

In your third week of pregnancy, it’s so early that you may have no idea that you are actually pregnant. Conception just happened, and there probably hasn’t been time for you to miss a period yet. At this point, traditional pregnancy symptoms may not have appeared as your hormones have not yet shifted.

In week 3 of pregnancy and the coming weeks, it’s time to start to be on the lookout for:

  • Missed period
  • Positive home pregnancy test
  • Positive blood pregnancy test

Baby is the size of: A few cells. While weeks 1 and 2 didn’t mean much for your baby, week 3 is when development starts to begin. After conception, your now-fertilized egg is on its way through a fallopian tube, dividing and re-dividing into identical cells as it travels to the uterus.

 

Week 4 of Pregnancy

First Trimester Week 4: A poppyseed

If you know you’re 4 weeks pregnant, you found out the news earlier than a lot of women do. Your first call at week 4 of pregnancy should be to your doctor to schedule your first prenatal visit, where they will confirm your pregnancy with a urine or blood test.

Now that you are pregnant, pregnancy hormones will begin to increase rapidly and cause pregnancy symptoms:

  • Bloating
  • Mild cramping
  • Spotting
  • Mood swings
  • Morning sickness
  • Fatigue
  • Sore breasts

Baby is the size of: A fraction of a poppy seed. Your baby is a small cluster of cells situated comfortably in your uterus to prepare for upcoming development.

 

Week 5 of Pregnancy

First Trimester Week 5: An appleseed

The fifth week of pregnancy is a common time for moms-to-be to find out they’re pregnant, as this is typically when a missed period is noticed. Plus, heightened hormone levels may be giving you pregnancy symptoms that are tough to ignore. You still won’t be seeing any physical changes to your body, but you might start to feel the internal changes.

At this point, your pregnancy symptoms may vary – you may feel none at all or feel them off and on: 

  • Sore breasts
  • Morning sickness
  • Fatigue
  • Frequent urination
  • Cramps
  • Spotting

Baby is the size of: An appleseed. Your baby is already starting to form major organs (heart, stomach, liver and kidneys) and systems (digestive, circulatory and nervous). Within the next week, your baby will grow quickly and double in size!

 

Week 6 of Pregnancy

First Trimester Week 6: A pea

At week six, pregnancy is still new to you, so it’s normal to feel a little emotional. The emotions you are feeling are likely exasperated by the rapidly increasing pregnancy hormones. At this point, you still aren’t likely to see many physical changes in your body aside from potential bloating.

Just like the fifth week of pregnancy, you may or may not feel pregnancy symptoms strongly, but you may feel:

  • Fatigue
  • Nausea
  • Sore breasts
  • Frequent urination
  • Gas and bloating
  • Mood swings
  • Cramping and spotting

Baby is the size of: A pea. Your baby at week 6 is now circulating blood with an increasingly sophisticated circulatory system. They might even start wiggling their hands and feet, and their nose, eyes, ears, chin, and cheeks start to form.

 

Week 7 of Pregnancy

First Trimester Week 7: A blueberry

Not much has changed since last week, but you might start to experience some new pregnancy symptoms. And since there are likely still no changes in your physical appearance, it might become more difficult to keep your pregnancy a secret knowing something everyone else doesn’t!

In this week, you may experience a shift in pregnancy symptoms:

  • Nausea
  • Food cravings and/or aversions
  • Frequent urination
  • Acne
  • Extra saliva
  • Mood swings
  • Cramping and/or spotting

Baby is the size of: A blueberry. Your embryo at this point is developing a more complex heart and brain, generating about one hundred new brain cells each minute. This is also when arm and leg joints begin to form.

 

Week 8 of Pregnancy

First Trimester Week 8: A raspberry

The eighth week of your pregnancy is when you will typically have your first prenatal appointment. For many, this step makes it all feel more real, as you may be able to finally meet your baby through an ultrasound and hear their heartbeat. This week is also when you might start feeling pregnancy symptoms a little more intensely.

During this time, your pregnancy hormones may start to impact you a bit differently than previous first trimester weeks:

  • Sore breasts
  • Fatigue
  • Morning sickness
  • Heightened sense of smell
  • Pregnancy cramps
  • Constipation
  • Weird dreams
  • Spotting

Baby is the size of: A raspberry. At 8 weeks, your baby’s fingers and toes are only slightly webbed, and their tail is gone. This is also the time when your baby’s taste buds are beginning to form.

 

Week 9 of Pregnancy

First Trimester Week 9: A cherry

Pregnancy has of course felt real this entire time, but week 9 is the time to start thinking about how pregnancy will affect other aspects in your life. Start looking into things like your finances, living situation, and job expectations so things stay as stress-free as possible once your baby arrives. This is also when you may start to show!

Week 9 is, unfortunately, when you are likely hitting your peak hormone levels, making these symptoms more intense:

  • Mood swings
  • Morning sickness
  • Frequent urination
  • Fatigue
  • Nasal congestion
  • Headaches

Baby is the size of: A cherry. During this time, your baby has grown quite a bit since last week and is starting to form more distinct facial features.

 

Week 10 of Pregnancy

First Trimester Week 10: A strawberry

Finally, what many moms-to-be look forward to! Your baby bump becomes more noticeable around week 10, which is always an exciting development. This week is another milestone as well: your baby is no longer an embryo and has grown into a fetus.

Your tenth week of pregnancy is when you start seeing physical change, which also affects new pregnancy symptoms:

  • Round ligament pain
  • Growing breasts
  • Morning sickness
  • Mood swings
  • Fatigue
  • Increased vaginal discharge
  • Visible veins

Baby is the size of: A strawberry. As noted, your baby is now a fetus. They now have working arm joints, and cartilage and bones are forming along with fingernails and hair. Your baby is also busy practicing swallowing and kicking.

 

Week 11 of Pregnancy

First Trimester Week 11: A lime

As the second trimester gets closer and closer, it might be time to start thinking ahead. The second trimester is a great time to have a babymoon, so start planning! Having something to look forward to will help push you through the remaining first trimester weeks.

In week eleven, you will feel the typical classic symptoms, but may also notice some new changes in your appearance:

  • Fatigue
  • Nausea
  • Gas
  • Mood swings

Baby is the size of: A lime. Your baby can now move freely and is developing more detailed features. Tooth buds, hair follicles, nail beds, and more opaque skin are forming, and the webbing between fingers and toes is mostly gone.

 

Week 12 of Pregnancy

First Trimester Week 12: A plum

Every week closer to the end of your first trimester is more and more exciting. In the twelfth week of pregnancy, your hormones may start to tone down and you may finally start to feel relief from your early pregnancy symptoms. You are probably showing more obviously now, which is why many moms-to-be choose to reveal the big news at this point.

Thankfully, pregnancy symptoms in week 12 of pregnancy take it down a notch from previous weeks:

  • Increased discharge
  • Spotting
  • Headaches
  • Dizziness

Baby is the size of: A plum. Since entering the fetus stage, your baby has already mostly developed the important organs and systems. At this point, your baby is now developing their brain and learning reflexes.

 

Week 13 of Pregnancy

First Trimester Week 13: A lemon

Finally, the end of your first trimester! After 13 long weeks, you are about to enter an easier trimester and already one-third of the way through with your pregnancy. You are now one trimester closer to meeting your baby, and it is typically safe to share your exciting news with people if you feel comfortable.

One of the biggest perks of the end of the first trimester is the lessening of symptoms, and some exciting new ones:

  • Visible veins
  • Increase in energy
  • Increased sex drive

Baby is the size of: A lemon. At the end of the first trimester, your baby has developed vocal cords, teeth, and even fingerprints. All of that on top of the already incredible development of their organs and systems!

 

Navigating Your First Trimester

 

Your first trimester of pregnancy is a wild ride, from new emotions to feeling your way through weird and uncomfortable pregnancy symptoms. The pregnancy journey is a wonderful experience, and being prepared can help you feel more confident and comfortable through it. If you are in your first trimester after a battle with infertility, congratulations! Red Rock Fertility Center is always here to help you through every stage of your pregnancy, from conception to postpartum.