What to expect during the first trimester

Written by the Progyny Editorial Team. Reviewed by the Progyny Clinical Team — April 2026.

The first trimester begins at week 1 of pregnancy and lasts through week 13. This early stage is a time of rapid change for both you and your baby.

You may feel excited, nervous, or unsure as you adjust to being pregnant. It’s very common to have a mix of physical symptoms and emotions as your body begins to support a growing pregnancy.

What to expect physically

During the first trimester, your body is adjusting to changing hormone levels and increasing energy demands.

Many people notice changes early on, sometimes before they even realize they’re pregnant. Fatigue and nausea – often called morning sickness – are among the most common symptoms.

You may also notice:

• Tender or swollen breasts
• Food cravings or aversions
• Frequent trips to the bathroom
• Mild headaches
• Digestive changes, like constipation or heartburn

Symptoms can vary widely, and not everyone feels them in the same way.

Emotional changes

Hormonal shifts during early pregnancy can affect how you feel. It’s normal to have a range of emotions, sometimes all at once or in the same day.

You might notice mood swings or feel more emotional than usual. You may also have moments of anxiety or uncertainty, especially as you adjust to the idea of pregnancy.

At the same time, you may feel excited as you begin to think about what’s ahead. If your emotions start to feel overwhelming or interfere with daily life, talk with your healthcare provider.

Your baby’s development

Even though it may not be visible yet, your baby is growing quickly!

Early in pregnancy, the brain, spinal cord, and heart begin to form. Soon after, the heart starts beating, and small buds that will become arms and legs begin to appear. As development continues, major milestones include:

• Formation of major organs
• Development of fingers and toes
• Early facial features taking shape

By the end of the first trimester, your baby is about the size of a lime and has many essential structures in place.

Prenatal care and early appointments

Schedule your first prenatal visit as soon as you know you’re pregnant. Early prenatal care plays an important role in supporting a healthy you and a healthy pregnancy.

At your first appointment, your provider will likely:

• confirm your pregnancy
• estimate your due date
• review your medical history
• talk with you about nutrition, exercise, and lifestyle habits
• collect blood and test urine

These visits often include guidance on what you can expect in the coming weeks, what food and drinks to avoid, and prenatal vitamins, which include important vitamins like folic acid.

This is also a good time to ask questions and share any concerns you may have. It can help to make a list of them before you go can help.

Common concerns

Some symptoms during the first trimester can feel concerning, especially if you’re not sure what’s typical. While many changes are normal, there are times when it’s important to check in with your provider.

Contact your care team if you have:

• Severe or persistent nausea and vomiting
• Vaginal bleeding or heavy spotting
• Strong abdominal pain or cramping
• Fever

When in doubt, it’s always okay to reach out.

Taking care of yourself

The first trimester can be physically and emotionally demanding, so it’s important to take care of yourself in ways that feel manageable.

Try to rest when you’re feeling tired and eat small, frequent meals if nausea makes it harder to eat. Staying hydrated and taking a daily prenatal vitamin can also support your health.

It may also help to:

• Stay as active as you were before pregnancy, but be careful when it comes to your torso and abdominal area
• Focus on sleep when possible
• Ask for support from family or friends
• Take ginger to help with nausea

Small adjustments can make a big difference during this time.

Looking ahead

This is the beginning of your pregnancy journey. While it can come with challenges, it’s also a time of important growth and development.

When people move into the second trimester, many begin to feel more energy and less of the early symptoms. For now, try to focus on caring for yourself and staying connected with your provider.

Progyny is here for you, too. Please contact your Progyny Care Advocate for support.

Recommended reading

• What should I look for in a prenatal vitamin?
• Your guide to healthy eating during pregnancy

Disclaimer: The information provided by Progyny is for educational purposes only and is not medical advice. Always consult a qualified healthcare provider for medical guidance.

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