Week 6
Your baby is the size of a lentil
What's happening this week
Your baby is now about the size of a lentil — roughly 4 to 5mm — and is developing at a pace that's hard to comprehend. This week brings one of pregnancy's most emotional milestones: cardiac activity may now be detectable on a transvaginal ultrasound.
To be precise about what's happening: the developing cardiac cells are generating rhythmic electrical pulses that create a visible flicker on ultrasound. It's not yet a fully formed heart with four chambers and valves — that comes later — but seeing that flicker for the first time is a moment many parents describe as the first time the pregnancy felt real. If your provider does an early ultrasound and doesn't detect cardiac activity yet, don't panic — it may simply be too early, especially if your dates are off by even a few days.
This week, tiny buds are appearing on the embryo that will become arms and legs. The beginnings of facial features are emerging: depressions where the eyes will be, small folds that will shape the ears, and a thickening where the mouth and jaw will form. The embryo has a curved, C-shaped posture and actually has a small tail-like structure — a remnant of development that will disappear in the coming weeks.
Inside, the digestive tract is taking shape as a long tube, and the foundations of the liver, kidneys, and lungs are being laid down. The embryo's circulatory system is becoming more organized, with blood beginning to flow through a simple but functional network of vessels.
Your body this week
If morning sickness hasn't arrived yet, this may be the week it makes its entrance. And let's be honest about the name: 'morning sickness' is a misnomer. For many people, nausea can last all day, hit hardest in the evening, or come in unpredictable waves. It's driven by rapidly rising hCG levels, and it typically peaks between weeks 8 and 10.
Some practical tips that many parents find helpful: eat small amounts frequently rather than large meals, keep plain crackers by your bed for before you stand up in the morning, stay hydrated (sipping water or ginger tea), and avoid strong smells that trigger nausea. If you can't keep food or fluids down for more than 24 hours, contact your healthcare provider — severe nausea and vomiting (called hyperemesis gravidarum) affects a small percentage of pregnancies and may need treatment.
Beyond nausea, you might notice heightened sense of smell, food aversions (foods you normally love might suddenly seem repulsive), increased saliva, and continued fatigue. Mood swings are common too — you might feel elated one moment and tearful the next. Blame the hormones, because they're surging.
Many providers won't schedule your first appointment until week 8 or later, so this can feel like a long, uncertain wait. If the anxiety of waiting is weighing on you, it's okay to call your provider's office and ask questions — that's what they're there for.
For dads
Welcome to the nausea weeks. If your partner is experiencing morning sickness, you're about to learn that the name is deeply misleading — it can strike at any time of day and can range from mild queasiness to being unable to keep anything down. This isn't something she can willpower her way through; it's caused by a massive hormone surge that's essential for the pregnancy. Your job isn't to fix it — it's to adapt around it. Learn which smells trigger her nausea (cooking smells are a common one) and find workarounds. Maybe you do the cooking in a well-ventilated kitchen, or you bring home takeout on the worst days.
Here's something nobody tells new dads: it's normal to feel a little left out right now. The pregnancy is happening inside your partner's body, the appointments are for her, and you might feel like a spectator. That feeling is valid — and it will shift as the pregnancy progresses. For now, one thing you can do: start a shared note on your phone where you both jot down questions for the first prenatal appointment. Having a list ready makes the visit more productive, and building it together keeps you involved in the process.
Common concerns
Is it normal for nausea to come and go?+
Completely normal. Morning sickness doesn't follow a predictable pattern for most people. You might feel terrible one day and fine the next, or nauseous in the morning but okay by afternoon. Fluctuating symptoms don't mean anything is wrong — they reflect the natural variation in how your body responds to rising hormone levels.
Will my provider do an ultrasound at 6 weeks?+
It depends. Some providers offer an early dating ultrasound between weeks 6 and 8, while others wait until the standard anatomy scan at 18-22 weeks. An early ultrasound is more likely if you have a history of ectopic pregnancy, are experiencing bleeding or pain, or conceived through fertility treatment. If you don't have an early scan scheduled, that's normal — it doesn't mean anything is wrong.
Does morning sickness mean my baby is healthy?+
There's a common belief that morning sickness is a 'good sign,' and some studies have found a correlation between nausea and lower miscarriage risk. However, the absence of morning sickness does NOT mean your pregnancy is unhealthy. About 20-30% of people have healthy pregnancies with little or no nausea. Your provider evaluates your pregnancy's health through checkups and tests — not based on how sick you feel.
When should I worry about vomiting in pregnancy?+
Mild to moderate nausea and occasional vomiting are normal in early pregnancy. However, contact your healthcare provider if you can't keep any food or fluids down for more than 24 hours, if you're losing weight, if you feel dizzy or faint, or if you see blood in your vomit. Severe nausea and vomiting (hyperemesis gravidarum) affects about 1-3% of pregnancies and may require medical treatment to prevent dehydration.
Product picks for week 6
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Ginger chews for nausea
Natural ginger candies that many parents find helpful for taking the edge off morning sickness — keep a bag in your purse or desk.
Sea-Band acupressure wristband
Gentle pressure on the P6 acupressure point — drug-free nausea relief you can wear all day.
Pregnancy milestone cards
A set of photo cards marking each week and milestone — start documenting your journey now while it's still early.
A quick note: This content is for informational purposes only and is not a substitute for professional medical advice. Always talk to your healthcare provider about any questions or concerns. Learn how we create our content.
Content based on guidance from the American College of Obstetricians and Gynecologists (ACOG), the American Academy of Pediatrics (AAP), Mayo Clinic, and peer-reviewed medical literature. Learn more about how we create our content.