The First Trimester of Pregnancy: What to Expect

Pregnancy can be beautiful, weird, a little gross, and often challenging. It is also a powerful glimpse into how strong women are. Every woman has a unique pregnancy experience. My own two pregnancies had some similarities between them and a lot of differences. While nothing can fully prepare you for what you’ll experience throughout pregnancy, it’s important to inform yourself of what’s likely to come, whether you are currently pregnant, preparing to become pregnant, or supporting a loved one.

I think of the first trimester of pregnancy as a shock to our system. Our body is trying to keep up with an increase in hormones while adapting to a rapidly growing embryo. I had no idea something so tiny could affect my body in such a large way.

Here’s what can happen during the first trimester, week-by-week.

The First Trimester: Weeks 1 + 2

Body and mind

Not pregnant yet! In weeks one and two of the first trimester, a menstrual cycle has come and gone, and the body is preparing for conception. Because the exact date of conception can be hard to calculate, healthcare providers will mark the first day of pregnancy based on the first day of a woman’s last period. However, conception does not actually occur until week three.

How to cope: Live your normal routine

You may be taking prenatal vitamins, swearing off alcohol, and changing your lifestyle a bit—just to be safe. Or you may be completely unaware this is the month. Either way, the main event is about to begin.

The baby

The little baby is still a dream or not even on your radar yet.

The First Trimester: Weeks 3 + 4

Body and mind

It’s conception and implantation time. While some women experience early pregnancy symptoms, such as mild cramping, breast tenderness, fatigue, and change in appetite, most are still entirely in the dark that their body is in the early stages of pregnancy.

How to cope: Wait with anticipation

If you track your ovulation and are trying to patiently wait for the appropriate time to get an accurate pregnancy test, keep yourself distracted and allow yourself to rest. Additionally, there’s a lot of information that makes your mind race and worry at this time, especially around miscarriages. Take a step back from Dr. Google this week. In fact, let’s agree that Dr. Google should be our very last consultant for crucial medical information. If you are experiencing severe symptoms such as severely painful cramping, call your healthcare provider.

The baby

The developing baby is called an embryo from conception through week eight of the first trimester. It is currently a small cluster of cells, no bigger than a sesame seed. The sex, eye color, hair color, and other features of your baby are already decided. The placenta is also starting to form and will produce the pregnancy hormone that pregnancy tests detects—human chorionic gonadotropin (hCG).

Though minuscule, the baby is going through rapid development right now. This tiny cell bundle is beginning to develop a brain, spinal cord, heart, and more.

The First Trimester: Weeks 5 + 6

Body and mind

You’ve missed your period, and it’s time to get out the home pregnancy tests. If the test is positive, you’re not experiencing any noticeable physical changes to your body, but the early pregnancy symptoms may be more prevalent than before.

A feeling of overwhelming excitement and fear is normal. Share the news with your partner and let them know how you’re feeling, no matter how that is.

If you have a negative test but have missed your period, give yourself a few days to a week to retry.

How to cope: Get the necessary healthcare and nutrients

Reach out to your obstetrician (OB of OB/GYN) to let them know about your positive pregnancy test. Typically they will wait to schedule your first appointment for week eight. If you don’t have an OB or wish to work with a midwife, now is a great time to do your research. Ask friends or local mom groups for their recommendations and experiences.

If you are facing an unexpected pregnancy, talk to a trusted friend or family member about your feelings and the options you are considering. If you are considering an abortion, seek out a trusted healthcare provider to talk about. the process and your options. For example, abortions performed in the first trimester are safer and easier.

At this time, you’ll want to start taking a daily prenatal vitamin. Prenatal vitamins help get essential nutrients to your baby, including folate, calcium, and iron. A wide range of options are available. Be aware that some may not be compatible with your early pregnancy symptoms. My prenatal vitamins magnified my morning sickness, and I had to switch to a gummy version. It’s OK to experiment with the time of day you take them, different brands, and various forms to find the right fit for you.

Your baby

The embryo is still tiny but rapidly growing from 3mm in week five to 19mm in week six. The development has begun of the eyes, ears, lungs, a jaw, nose, and hand and leg buds. A heartbeat is finding its rhythm and can be detected on an ultrasound. After seeing the heartbeat, the risk of miscarriage drops down to 10-15 percent.

The First Trimester: Weeks 7 + 8

Body and mind

Your uterus has grown from the size of your fist to the size of a grapefruit. Externally, you may not be showing but internally, things are beginning to shift.

Morning sickness is likely rearing its ugly head due to the increase in hormones. Despite the name, it can hit morning, afternoon, night, or all day. You may experience aversions to certain smells and foods, and fatigue may be taking a more significant toll on your body, causing you to experience “pregnancy brain”—a foggy mind and forgetfulness—for the first time.

If you are one of the lucky ones not experiencing morning sickness or other early pregnancy symptoms, it means your body is doing a great job at tolerating the increase in hormones. Congrats to you!

How to cope: Manage your morning sickness and your new little secret

One thing I learned about morning sickness management is that one size does not fit all. There is a wealth of tips available to read, but not all will be your saving grace. I read endless suggestions for ginger, fruit smoothies, tea, and more remedies but nothing worked to pull me out of the never-ending hangover I felt stuck in. Eating small portions of very bland food to keep my stomach from hitting empty was the most my body would allow. Plus lots of sleep, water, and electrolyte beverages. The healthy nutrition would have to wait. Collect the tips and suggestions but listen to your body above all.

Now that you’ve seen the little heartbeat rhythms, sharing the news with family and friends is 100 percent up to your personal preference. You may decide to wait until you’re out of your first trimester. You may want to share the news with a few select family or friends to grow your support network right away. You may want to scream your excitement to the whole world. The choice is yours; there is no right or wrong way.

Your baby

Every vital organ has begun to develop, and the embryo is growing to just over an inch as the trunk starts to stretch and straighten out. Hair, nipples, eyelids, and toes are all developing and forming while the embryonic tail is disappearing.

The First Trimester: Weeks 9 + 10

Body and mind

Mood swings, bloating, and heartburn only add to early growing pains of the body adapting to pregnancy. You may find yourself crying at things neither sad nor sentimental. Your pants fit a bit snug. A single cheerio causes your chest to feel like it’s burst into flames. It can be miserable—really miserable—but it’s not forever. Relief from these early pregnancy symptoms will likely come in the first half of the second trimester.

How to cope: Move your body

Staying active is the last thing you want to do in the midst of feeling sick and exhausted, but it can be the very thing that gives you a little physical and mental relief. Keep it simple if you need to, even if it’s a short walk, 10 minutes of yoga, or a set of lifting weights. Find what feels good.

Your baby

These weeks mark the end of the embryonic period. The embryo is now a fetus. Fetal growth and development helps prepare the baby for life outside the womb. The fetus, measuring around two inches, is starting to resemble a tiny baby now that the embryonic tail is gone. Joints are working, allowing it to float around the amniotic sac. Vital organs are functioning as well, but will continue to mature over the weeks to come.

The most delicate and critical development period is over as most congenital conditions appear by this time.

The First Trimester: Weeks 11 + 12

Body and mind

The end of the first trimester is here! Early pregnancy symptoms are still in full force but may start to diminish over the next few weeks. An increase in nail and hair growth is typical due to the higher levels of a hormone called androgen. Enjoy the fuller hair and longer nails but don’t be alarmed if less desirable body hair starts to be more prevalent too. Chin hairs, belly hairs, nipple hairs, and more can to be more abundant.

How to cope:  Know your strength

Now that you’ve approached the end of the first trimester, you’ve started to wrap your mind around the fact your body is growing a little human. Your body is its safe home. This realization paired with society’s general attitude that pregnancy is a “condition” can leave you feeling fragile. But the important thing to know is you are not instantly breakable. You are growing a developing baby 24/7 while managing the physical, emotional, and mental strains of pregnancy while also going about your daily work and life routines. You are strong as hell.

Your baby

The fetus has grown to over three inches. The kidneys are able to secrete urine and the suckling reflex begins. You may catch a cute glimpse of thumb-sucking on the ultrasound. The fetus is more active, but you won’t be able to feel the movement for a few more weeks.

Prepare Yourself for the Second Trimester

While some like to roll with the punches, many women—especially if this is your first pregnancy—like to anticipate what they might expect next. To familiarize yourself with the second trimester, head to the next article in this series.

Get our weekly digest for advice on sex, periods, and life in a female body


Continue the conversation

Leave a Reply

Your email address will not be published. Required fields are marked *