How Soon Can Morning Sickness Begin? | First Signs By Week

Morning sickness can sneak up fast. One week you’re fine, then brushing your teeth turns into gagging, coffee smells strange, and the drive to work feels like a roller coaster. If you’re newly pregnant (or trying), the timing question comes early: when can nausea start, and what’s a normal range?

Below, you’ll get a clear week-by-week window, what early symptoms can look like before vomiting starts, and the red flags that mean you should contact your obstetric team. You’ll also get practical ways to eat and hydrate when your stomach wants to veto all foods.

What Morning Sickness Is And Why The Start Date Shifts

“Morning sickness” means nausea, with or without vomiting, during pregnancy. The nickname is misleading. It can hit at any hour, and some people feel sick all day.

The start date shifts because pregnancy changes don’t rise on the same timetable for all people. Hormone levels climb at different speeds, smell sensitivity can spike early or later, and an empty stomach can trigger nausea in one person while another feels worse after meals.

Most medical sources describe a first-trimester pattern. ACOG notes that nausea and vomiting of pregnancy usually starts before 9 weeks, and for many women it goes away by 14 weeks. ACOG’s patient FAQ on nausea and vomiting of pregnancy lays out that common window and lists care options used in practice.

How Soon Can Morning Sickness Begin? Early Timing By Week

If you’re watching the calendar, the earliest realistic start that shows up across references is around week 4 of pregnancy. That’s often close to when a period is missed. Mayo Clinic’s first trimester overview notes that morning sickness often begins between 4 and 9 weeks. Mayo Clinic’s first trimester “what to expect” page describes that range.

Many people feel the first real shift in weeks 6–8. That’s the window where nausea becomes more than “a weird day,” and starts shaping meals, commuting, and sleep. RCOG’s pregnancy sickness patient information describes a similar early start range.

Week 4 To Week 5: Early Hints, Not Always Vomiting

At weeks 4–5, nausea can feel like mild queasiness, quick appetite changes, or a sudden “nope” reaction to smells. Vomiting can happen, yet plenty of people never vomit at all.

Because week 4 is early, nausea can overlap with reflux, stomach bugs, or stress. Pregnancy nausea tends to repeat day after day and often comes with smell triggers or an empty-stomach wave that eases after small bites.

Week 6 To Week 8: When It Usually Becomes Obvious

This is the common onset window. You might wake up queasy, feel worse during toothbrushing, or gag when you open the fridge. Food dislikes can be intense and oddly specific. One brand of yogurt is fine. Another makes you run.

If you’re not sure where you are in pregnancy, dates can be off. If ovulation happened later than usual, your “week 6” on paper might be closer to week 5 in real time. That mismatch is one reason the start date feels unpredictable.

Week 9 To Week 12: When Many People Feel The Peak

For many pregnancies, this stretch is the rough patch. Nausea may last longer into the day, vomiting can be more frequent, and smell triggers can feel unavoidable.

During this phase, focus less on perfect meals and more on “what stays down.” Hydration and calories matter more than variety. If you can keep fluids down and you’re peeing several times a day, you’re usually in a safer zone. If you can’t keep fluids down, act quickly.

Week 12 To Week 14: A Common Turning Point

Many people start getting breaks in this window. You might feel normal for a few hours, then queasy, then fine again. That pattern often signals improvement. Some people still feel sick past this point, and that can still happen in an otherwise healthy pregnancy.

Signs That Count As Morning Sickness Even If You Never Throw Up

Vomiting gets all the attention, yet early pregnancy nausea often shows up in quieter ways:

• Queasiness that comes in waves
• Food aversions (a once-loved food suddenly feels wrong)
• Strong smell reactions (coffee, perfume, cooking oil)
• Gagging while brushing teeth
• Feeling worse with an empty stomach
• Excess saliva or frequent spitting

If you’re wondering whether this can start before a positive test: it can. If your cycles are regular, week 4 nausea can line up with the days you first test. If your cycles vary, timing can shift by a week or more.

Common Triggers That Make Symptoms Start Or Feel Worse

Pregnancy sets the stage, then daily triggers decide how bad it feels. These are the ones people report most:

Empty-stomach gaps

Long stretches without food can make nausea spike. Many people feel better with small, frequent bites. Think in snacks, not big meals.

Heat and strong odors

Warm kitchens, frying smells, and perfume can flip nausea on. Cold foods can be easier because they smell less. Ventilation helps more than you’d think.

Toothbrushing

Brushing teeth can trigger gagging. A milder toothpaste flavor, a smaller amount of paste, or brushing later in the morning can help.

Prenatal vitamins

Some prenatal vitamins upset the stomach, often because of iron. Taking vitamins with food or at night can reduce nausea. If a vitamin makes you vomit, ask your clinician about options.

When It’s Within The Usual Range And When To Call

Mild to moderate nausea is common. Vomiting can also be common. The line that matters is hydration and function: can you keep fluids down, keep some food down, and get through your day?

Contact your clinician the same day if any of these happen:

• You can’t keep liquids down for 24 hours
• You feel faint or you can’t stand without dizziness
• You pee little, or urine is dark and strong-smelling
• You vomit blood, or you have severe belly pain
• You lose weight without trying

Severe nausea and vomiting can progress to hyperemesis gravidarum, which can cause dehydration and metabolic problems and may need medical care. StatPearls notes that hyperemesis gravidarum typically begins between 4 and 6 weeks of gestation. NCBI Bookshelf: StatPearls on hyperemesis gravidarum summarizes typical onset and the clinical features that raise concern.

Table: Week-by-week pattern, what it feels like, what helps

Use this as a rough map. Your experience can land earlier, later, lighter, or heavier.

Pregnancy week range	What symptoms can feel like	Moves that often help
Week 4	Mild queasiness, smell sensitivity, appetite shift	Keep crackers by the bed; try cold drinks
Week 5	Nausea waves, early aversions, gagging with brushing	Snack every 1–2 hours; switch toothpaste flavor
Week 6	More frequent nausea; occasional vomiting	Eat before getting up; avoid strong cooking smells
Week 7	Food dislikes widen; fatigue stacks with nausea	Choose bland carbs plus protein; sip fluids all day
Week 8	Smells trigger faster; gag reflex stronger	Cold meals; fresh air breaks; small portions
Week 9–10	Harder mornings; nausea lasts longer in the day	Plan “safe foods”; keep snacks in your bag
Week 11–12	Peak for many; vomiting can be more frequent	Ask about B6 + doxylamine; protect hydration
Week 13–14	More breaks; vomiting may ease	Rebuild meal variety slowly; keep a snack routine
Week 15–20	Symptoms fade for many; some still feel sick	Review care plan; check for dehydration signs

What To Do The First Week You Feel Sick

When nausea hits, it’s tempting to wait it out. A steadier plan works better. Start with food timing and fluids, then step up as needed.

Start mornings with two bites

Before you stand up, take two bites of something plain: crackers, dry cereal, or a small piece of toast. Wait a few minutes, then sit up slowly. This can blunt the empty-stomach surge.

Eat like a grazer

Set a timer and eat a small snack every two hours. A small, steady stream often beats three big meals. If you feel nauseated, your stomach may tolerate bland carbs. Pair them with a small protein when you can: yogurt, nuts, cheese, eggs, or broth with shredded chicken.

Make drinks easier than water

If plain water tastes wrong, switch tactics. Ice chips, cold sparkling water, diluted juice, oral rehydration drinks, or ginger tea can go down more smoothly. Tiny sips every few minutes can beat big glasses.

Change food temperature

Hot foods smell stronger. Cold foods smell less. That alone can turn a “no” into a “maybe.” Try cold pasta, fruit, cereal, smoothies, or sandwiches.

Use simple nausea aids

Many care plans start with vitamin B6 and doxylamine, plus food and routine changes. ACOG lists these options and when to step up care. If you want to try supplements or over-the-counter medicines, ask your clinician about dosing and safety for you.

Table: Small swaps that can rescue a day

Problem pattern	Small swap	What “better” looks like
Nausea hits before breakfast	Snack in bed, then stand up slowly	Less gagging during the morning routine
Long gaps between eating	Snack timer every two hours	Fewer empty-stomach waves
Water is a trigger	Ice chips or sparkling water	Urine gets lighter through the day
Cooking smell sets you off	Cold meals and strong ventilation	Fewer smell-driven spikes
Brush-and-gag cycle	Milder toothpaste flavor	Less retching during hygiene
Evenings feel worse	Protein snack mid-afternoon	Less late-day nausea creep
Prenatal vitamin causes vomiting	Take with food or at night; ask about switching	Fewer vitamin-linked flares

What It Means If You Have No Morning Sickness

Some people never get nausea, and many still have healthy pregnancies. Symptoms are not a scorecard. What matters is your prenatal care, growth checks, and the guidance you get from your clinician for your specific health history.

Three Takeaways To Keep On Your Phone

• Nausea can start around week 4, and weeks 6–8 are a common onset window.
• Many people feel worst in weeks 9–12 and start improving around weeks 12–14.
• If you can’t keep fluids down or you’re peeing little, contact your clinician the same day.