First Trimester Survival Guide: What to Expect in Weeks 1-12

The first trimester can feel like a whirlwind of emotions and physical changes. From the moment you see that positive test to your first ultrasound, there’s so much happening — even if it doesn’t look like it from the outside.

What happens during the first trimester?

The first trimester spans weeks 1 through 12 of pregnancy. During this time, your baby goes from a single fertilized cell to a fully formed (though tiny) fetus about the size of a lime. Meanwhile, your body is working overtime to create the placenta and adapt to pregnancy hormones.

Early pregnancy symptoms to expect

Every pregnancy is different, but common first trimester symptoms include:

• Nausea and morning sickness — Despite the name, it can strike at any time of day. About 70-85% of pregnant people experience some degree of nausea. ^{1 2}
• Fatigue — Growing a human is exhausting. Your body is producing more blood and your progesterone levels are soaring.
• Breast tenderness — Hormonal changes can make your breasts feel sore, swollen, or tingly.
• Frequent urination — Your growing uterus puts pressure on your bladder.
• Food aversions and cravings — Suddenly can’t stand the smell of coffee? That’s normal.
• Mood swings — Blame the hormones. It’s okay to feel all the feelings.

Managing morning sickness

Morning sickness affects most pregnant people to some degree. Here are evidence-based strategies:

1. Eat small, frequent meals — An empty stomach makes nausea worse.
2. Keep crackers by your bed — Eat a few before getting up in the morning.
3. Try ginger — Ginger tea, ginger candies, or ginger ale (with real ginger) can help.
4. Stay hydrated — Sip water throughout the day. Add lemon if plain water is unappealing.
5. Vitamin B6 — ACOG recommends vitamin B6 as a safe first-line treatment for pregnancy nausea. Talk to your provider about the right dose. ¹
6. Acupressure bands — Some people find wrist pressure bands (like Sea-Bands) helpful.

If you’re vomiting multiple times a day and can’t keep food or fluids down, contact your healthcare provider. This could be hyperemesis gravidarum, which requires medical treatment. ¹

Essential first trimester nutrition

Your baby’s neural tube (which becomes the brain and spinal cord) forms in the first few weeks — often before you even know you’re pregnant. Key nutrients include:

• Folate/Folic acid — 600 mcg daily during pregnancy (400 mcg before conception). Critical for neural tube development. ³
• Iron — Your blood volume increases by 30–50% during pregnancy. You need 27 mg daily. ^{3 4}
• DHA — An omega-3 fatty acid important for brain development. ⁴
• Calcium — For your baby’s developing bones and teeth. ⁴
• Prenatal vitamins — Start taking them as soon as possible if you haven’t already. ³

First trimester doctor visits

You’ll typically have your first prenatal appointment between weeks 8-10. Expect:

• A confirmation of pregnancy and estimated due date
• Blood tests (blood type, Rh factor, iron levels, immunity checks)
• Discussion of your medical history and any risk factors
• Possibly an early ultrasound to confirm the pregnancy and check for multiples
• Information about genetic screening options ⁵

When to tell people you’re pregnant

There’s no “right” time. Many people wait until after the first trimester (when miscarriage risk drops significantly), but this is entirely your choice. Consider telling your partner and a close support person early, as the first trimester can be physically and emotionally challenging.

Tracking your pregnancy with Nooko

The first trimester is full of questions, milestones, and things to remember. Nooko helps you track symptoms, count down to appointments, and understand exactly what’s happening with your baby’s development — week by week.

References

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Footnotes

1. Morning Sickness: Nausea and Vomiting of Pregnancy. American College of Obstetricians and Gynecologists. Reviewed November 2025. ↩ ↩² ↩³

2. Nausea and Vomiting of Pregnancy. American Academy of Family Physicians. American Family Physician. 2003;68(1):121-128. ↩

3. Healthy Eating During Pregnancy. American College of Obstetricians and Gynecologists. Reviewed December 2025. ↩ ↩² ↩³

4. Pregnancy Diet: Focus on These Essential Nutrients. Mayo Clinic. Updated January 2025. ↩ ↩² ↩³

5. Current ACOG Guidance on Prenatal Screening. American College of Obstetricians and Gynecologists. ↩