Week 6
Your baby is about 2 to 4 mm long this week (around 1/8 in), roughly the size of a lentil, though every embryo grows at its own pace. Counted from conception, the embryo is only about three weeks old. Even so, it is busy: the neural tube that becomes the brain and spinal cord is closing, and a simple tube of a heart has started to beat. For you, this is often the week pregnancy stops feeling theoretical. Nausea, a sharper sense of smell, more trips to the bathroom and quick shifts in mood can all arrive now. The focus this week is learning what is normal, knowing the few warning signs that are not, and getting ready for your first prenatal visit.
Day 36 · 5 weeks 0 days
A tiny heart has started to beat
Somewhere around now, a small tube of muscle in your baby's chest begins to pulse. It is not yet a heart with chambers and valves. It is a single folded tube that twitches in a steady rhythm, pushing blood through the earliest blood vessels. Over the next few weeks it will loop, fold and divide into the four-chambered heart your baby will be born with.
At the same time, the neural tube is closing. This groove along the embryo's back seals over to become the brain at one end and the spinal cord along its length. It is the reason folic acid matters so much in these early weeks, and why you were encouraged to keep taking it every day. You will not feel any of this, and it is too early for most scans to show it clearly. If you have an ultrasound in the next week or two and the flicker of a heartbeat is not seen yet, that is often simply a matter of timing. Dates based on your last period can easily be a few days off.
Try this: Check that your prenatal vitamin with folic acid is somewhere you will see it every day, next to your toothbrush or your keys.
Day 37 · 5 weeks 1 day
Morning sickness rarely keeps to the morning
For many people, nausea shows up around now. Somewhere between 7 and 8 in 10 pregnant people feel sick at some point in the first trimester, and about half vomit. The name "morning sickness" is misleading. It can come at any hour, and for some it lasts all day.
Nobody knows the exact cause, but it tracks closely with rising pregnancy hormones, especially hCG. It usually builds over the next few weeks, peaks somewhere between 8 and 12 weeks, and eases for most people by 16 to 20 weeks. A smaller group feels it for longer.
Nausea is unpleasant, but ordinary nausea does not harm your baby. In the early weeks the embryo needs very little energy, and it draws what it needs from your stores. If you can only manage plain toast and crackers for a while, that is all right. Keep taking your prenatal vitamin if you can; if it makes you queasy, try it at bedtime or with a snack.
Having no nausea at all is also normal. Plenty of healthy pregnancies come with very little sickness.
Try this: Keep a few plain crackers by your bed and eat one or two slowly before you sit up in the morning.
Day 38 · 5 weeks 2 days
Know the signs of an ectopic pregnancy
Most pregnancies settle safely in the uterus. In about 1 or 2 in every 100, the fertilized egg implants somewhere else, most often in a fallopian tube. This is called an ectopic pregnancy. It cannot continue, and as it grows it can cause the tube to rupture, which is a medical emergency.
Signs usually appear between about 5 and 10 weeks. They can include pain low in your abdomen, often on one side; vaginal bleeding or a brown, watery discharge; pain at the tip of your shoulder; pain when you pee or have a bowel movement; and feeling faint or dizzy. Some people have only mild symptoms at first.
Your risk is higher if you have had an ectopic pregnancy before, pelvic infection, surgery on your tubes, or conceived with an IUD in place or with fertility treatment. But it can happen to anyone.
Call your care provider if you have one-sided pain or any bleeding, even if it seems mild.
Get help right away if you have severe abdominal pain, shoulder tip pain, or you feel faint, dizzy or very unwell. Call your local emergency number or go to the nearest emergency department.
Try this: Save your care provider's after-hours number in your phone today, so you never have to hunt for it.
Day 39 · 5 weeks 3 days
Your nose is on high alert
Coffee brewing, a coworker's lunch, the inside of the fridge, your partner's shampoo. Smells you barely noticed a month ago may suddenly feel overwhelming. A heightened sense of smell is one of the most common early pregnancy changes, and it often travels with nausea.
Researchers are not sure exactly why this happens. Hormones seem to play a part, and some think it may once have helped steer pregnant people away from spoiled food. Whatever the reason, it is real, and it can make cooking, commuting and even hugging people harder.
Small changes help. Open windows when you cook, or let someone else cook strong-smelling foods for a while. Cold foods tend to give off less smell than hot ones. Some people carry something they find pleasant to sniff, like a slice of lemon, a mint or a fresh-smelling handkerchief, to cover an unwelcome odour.
You may also notice a metallic or sour taste in your mouth. This usually fades along with the nausea as the first trimester ends.
Try this: Notice which smells set you off today and write down the top three, so you can avoid or work around them.
Day 40 · 5 weeks 4 days
Why you need to pee so often already
It seems too early for the baby to be pressing on your bladder, and it is. The extra bathroom trips in early pregnancy have other causes. The hormone hCG increases blood flow to your pelvis. Your blood volume is starting to rise, and your kidneys are filtering much more fluid than usual, up to about half as much again by the middle of pregnancy. The growing uterus, still low in your pelvis, adds a little pressure too.
This usually eases in the second trimester, when the uterus rises out of the pelvis, and returns near the end when the baby drops lower.
Do not cut back on drinking to avoid the bathroom. You need fluids now more than ever. Instead, try drinking more earlier in the day and a little less in the hour or two before bed. Leaning forward when you pee can help empty your bladder fully.
Pregnancy also makes urinary tract infections more likely, and they need treatment.
Call your care provider if you have burning when you pee, a strong urge but only a small amount comes out, cloudy or bloody urine, pain in your lower back or side, or a fever.
Try this: Fill a large water bottle in the morning and aim to finish most of it before dinner.
Day 41 · 5 weeks 5 days
Up one hour, teary the next
If you have found yourself crying at an advertisement or snapping over a small thing, you are in good company. Mood swings are common in the first trimester. Rapidly rising hormones affect brain chemicals that shape mood. Add tiredness, nausea and the sheer size of the news, and it makes sense that feelings run closer to the surface.
You might feel thrilled and frightened in the same afternoon. You might feel less excited than you expected, or worry about things you cannot control. None of this says anything about the kind of parent you will be. Mood swings usually settle as the first trimester ends. Sometimes, though, low mood or worry is more than a passing wave. Depression and anxiety can begin during pregnancy, and they are treatable.
Call your care provider if you feel low or hopeless most days for two weeks or more, lose interest in things you usually enjoy, or feel anxious to the point that it gets in the way of daily life.
Get help right away if you have thoughts of harming yourself.
For your partner: When mood shifts come, try listening first rather than fixing or explaining. A simple "that sounds hard, what would help?" goes a long way.
Day 42 · 5 weeks 6 days
Getting ready for your first prenatal visit
Your first full prenatal appointment, sometimes called the booking visit, often happens somewhere between 8 and 12 weeks. It is usually one of the longest visits of your pregnancy, and it goes more smoothly if you gather some information beforehand.
Your care provider will want to know the date your last period started and how regular your cycles are. They will ask about past pregnancies, including miscarriages or terminations, and any long-term health conditions. Have a list of every medication, supplement and herbal product you take, with doses.
Family history matters too. It helps to ask relatives, on both the baby's biological parents' sides if you can, about conditions such as diabetes, high blood pressure, blood clots, heart problems, twins, or genetic conditions like cystic fibrosis, sickle cell disease or thalassemia.
Write down your own questions as they come up. In the moment, it is easy to forget the thing you wondered about at 3 a.m. No question is too small, whether it is about a symptom, your work or a food you are unsure of. Try this: Start a note on your phone or in a notebook titled "First visit" and add your medication list and three questions today.