While pregnancy tests and ultrasounds are the only way to know if you’re pregnant, you can look for other signs and symptoms like morning sickness, fatigue, and more.

Though it may sound odd, your first week of pregnancy is based on the date of your last menstrual period. Your last menstrual period is considered week 1 of pregnancy, even if you weren’t pregnant yet.

The expected delivery date is calculated using the first day of your last period. For that reason, you may not have symptoms during the first few weeks of your 40-week pregnancy.

If you’re pregnant, you may notice common early indicators. These can include:

Other signs may include:

About 10 to 14 days (week 4) after conception, you may experience implantation bleeding, which may be mistaken for a light period. It does not occur for everyone. If it does occur, it will usually happen around the time you expect your period.

Signs of implantation bleeding include:

  • Color: The color may be pink, red, or brown.
  • Bleeding: It’s often described as light bleeding that never turns into a flow or enough to need a tampon.
  • Pain: Though usually milder than menstrual pain, it may involve mild to severe cramping.
  • Timing: Bleeding episodes may last a few hours to a few days.

If you think you may be experiencing implantation bleeding:

  • Avoid smoking, drinking alcohol, or using drugs, which can be associated with heavy bleeding.

After implantation, your body starts making the hormone human chorionic gonadotropin (hCG), which helps maintain the pregnancy. It also tells the ovaries to stop releasing mature eggs each month.

You will likely miss your next period 4 weeks after conception. If you typically have an irregular period, you’ll want to take a pregnancy test to confirm.

Most home tests can detect hCG as soon as 7 days after a missed period. A pregnancy test detects hCG levels in your urine and shows if you are pregnant.

  • Know that a false negative is more likely than a false positive.
  • If you get a positive result, schedule an appointment with a doctor to confirm.
  • If you’re on any medications, ask a doctor whether they pose risks to the pregnancy.

When you’re pregnant, you may have a higher basal body temperature. Your core temperature may increase more easily with exercise or in hot weather. During this time, make sure to drink more water and exercise cautiously.

Fatigue can develop anytime during pregnancy. This symptom is common in early pregnancy. Rising progesterone levels can make you feel sleepy.

  • The early weeks of pregnancy can make you feel exhausted. Try to get enough sleep if you can.
  • Keeping your bedroom cool can also help you sleep better.

Around weeks 8 to 10, your heart may begin pumping faster and harder. Palpitations and arrhythmias are common in pregnancy. This is usually due to hormones.

Your blood flow can increase by around 50% during pregnancy. This adds to your heart’s workload.

It’s best to discuss any underlying heart conditions or medications you take with your medical team.

Breast changes can occur between weeks 4 and 6. You’re likely to develop tender and swollen breasts due to hormone changes. This will likely go away after a few weeks when your body has adjusted to the hormones.

Nipple and breast changes can also occur around week 11. Hormones continue to cause your breasts to grow. The areola — the area around the nipple — may grow darker and larger.

  • A comfortable, supportive, underwire-free maternity bra may help relieve breast tenderness.
  • A bra with varying clasps can give you room to “grow” in the coming months.
  • Breast pads that fit into your bra can reduce friction and nipple pain.

Your estrogen and progesterone levels increase during pregnancy and can make you more emotional or reactive than usual. Mood swings are common during pregnancy and may cause feelings of:

During pregnancy, your body increases the amount of blood it pumps. This causes the kidneys to process more fluid than usual, leading to more fluid in your bladder.

Hormones also play a large role in bladder health. During pregnancy, you may run to the bathroom more frequently or accidentally leak.

  • Drink about 300 milliliters (a little more than a cup) of extra fluids each day.
  • Plan out your bathroom trips ahead of time to avoid leaking urine.

Bloating may occur during early pregnancy due to hormone changes, which can also slow down your digestive system. You could feel constipated and blocked as a result.

Constipation can also increase feelings of abdominal bloating.

Nausea and morning sickness usually develop around weeks 4 to 6 and peak around week 9.

Although it’s called morning sickness, it can occur anytime during the day or night. It’s unclear exactly what causes nausea and morning sickness, but hormones may play a role.

Many people experience mild to severe morning sickness during the first trimester of pregnancy. It may become more intense toward the end of the first trimester but often becomes less severe as you enter the second trimester.

  • Keep a package of saltine crackers by your bed and eat a few before you get up in the morning to help settle morning sickness.
  • Stay hydrated by drinking plenty of water.
  • Talk with a doctor if you cannot keep fluids or food down.

In most cases, blood pressure will drop in the early stages of pregnancy. This may also cause feelings of dizziness since your blood vessels are dilated.

High blood pressure (hypertension) due to pregnancy is more difficult to determine. Almost all cases of hypertension within the first 20 weeks indicate underlying problems. It may develop during early pregnancy but may also be present beforehand.

A medical professional will likely take your blood pressure during your first doctor visit to help establish a baseline blood pressure reading.

  • Consider switching to pregnancy-friendly exercises, if you haven’t already.
  • Learn how to track your blood pressure regularly.
  • A doctor can provide dietary guidelines to help reduce high blood pressure.
  • Drinking enough water and snacking regularly can help prevent dizziness. Standing up slowly when getting up from a chair may also help.

Smell sensitivity is a symptom of early pregnancy that’s mostly self-reported. There’s little scientific evidence about smell sensitivity during the first trimester. However, it might be important since smell sensitivity may trigger nausea and vomiting. It may also cause a strong distaste for certain foods.

You may experience either a heightened or lessened sense of smell during pregnancy, according to 2017 research. This is especially common during the first and third trimesters. Heightened smell is more common than lessened smell. Some smells that never bothered you before may become less pleasing or even trigger nausea.

The good news is that your sense of smell usually returns to how it was before, after delivery, or within 6 to 12 weeks postpartum.

Weight gain can become more common at the end of your first trimester. You may gain about 1 to 5 pounds in the first few months.

Calorie recommendations for early pregnancy won’t change much from your usual diet but can increase as pregnancy progresses.

Hormones can cause the valve between your stomach and esophagus to relax. This allows stomach acid to leak, causing heartburn.

  • Eating several small meals a day instead of larger ones can help prevent heartburn.
  • Sitting upright for at least an hour after eating can help you digest.
  • If you need antacids, talk with a doctor about what may be safe during your pregnancy.

Many people may begin saying you have the “pregnancy glow.” Increased blood volume and higher hormone levels push more blood through your vessels. This causes the body’s oil glands to work overtime.

The increased activity of your body’s oil glands gives your skin a flushed, glossy appearance. On the other hand, you may also develop acne.

Using an at-home pregnancy test, you can generally know if you’re pregnant 1 week after you’ve missed a period.

While you can take a test earlier than this if you want, you risk getting a false negative result. If you take the test too early, there may not be enough hCG in your urine yet for the test to detect it.

Also, every person’s body is a bit different. One person may get a positive result as early as a day after their period, while another person’s positive results may not show up for another week.

Blood tests can often detect hCG earlier in a pregnancy than urine tests. Blood tests can give a positive result as early as 6 to 8 days after ovulation, while urine tests do so about 3 weeks after ovulation.

A medical professional usually does blood tests.

Pregnancy symptoms like nausea, fatigue, and breast tenderness sometimes occur even before you miss a period. These symptoms may give you the idea that you’re pregnant, but only a test will tell for sure.

If you think you might be pregnant, the best time to take a home pregnancy test is 1 week after you first miss a period.

A blood test can often reveal a pregnancy much earlier, but it must be done at a doctor’s office or clinical setting.

If you get a positive result on a home pregnancy test, you should call a doctor right away, according to the Office on Women’s Health. The doctor can prescribe a more sensitive test and perform a pelvic exam to determine if you’re pregnant.

The Office on Women’s Health recommends you make an appointment with a medical professional as early as possible in your pregnancy. You can then schedule regular prenatal visits throughout your pregnancy.

If you don’t already have an ob-gyn, you can browse doctors in your area through the Healthline FindCare tool.

Your body will go through significant changes in early pregnancy. You may see signs such as nausea, breast tenderness, and the hallmark symptom of a missed period.

Many body changes and symptoms of pregnancy you experience in the first trimester will start to fade once you reach the second trimester.

If you think you might be pregnant, a good first step is to take a home pregnancy test. Tests are widely available without a prescription in pharmacies and other stores.

If you receive a positive result, call a doctor for an appointment. They will perform an examination and a further test to confirm your pregnancy. You can then get started on a prenatal program to safeguard your and the fetus’s health.

To receive week-by-week guidance about early pregnancy symptoms and more, sign up for our I’m Expecting newsletter.

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