This is the week that pregnancy may first begin to feel real.

You may notice that your period isn’t starting when expected, and levels of human chorionic gonadotropin (hCG), the pregnancy hormone, are high enough during week four of pregnancy that a pregnancy test should detect them.

Many moms are starting to experience early symptoms of pregnancy, although others still may not even be aware they’re pregnant for a bit longer.

Your Baby’s Development At 4 Weeks Pregnant

Your baby is barely the size of the head of a pin. If you could take a peek, you wouldn’t be able to tell much about the baby’s features or development. Still, all those cells that continue to multiply rapidly are beginning to differentiate — to each take on their independent functions so that eventually they can take on different roles as skin, bone, brains, and other organs and parts.

Your baby now has an amniotic sac to help protect and cushion him or her and is beginning to sap nutrients from you through the placenta to grow and develop. However, at this stage, the baby also has a yolk sac to provide nourishment.

Quick Overview: Baby's Development At 4 Weeks Pregnant:

• Baby is barely the size of a pinhead and still too small to show distinct features.
• Cells are rapidly multiplying and differentiating to form skin, bones, organs, etc.
• The amniotic sac has formed to cushion and protect the baby.
• The baby is starting to receive nutrients from the placenta to support growth.
• At this stage, the baby also relies on the yolk sac for nourishment.

Mother’s Symptoms At 4 Weeks

Many (but not all!) moms are beginning to see early symptoms of pregnancy now.

You may struggle with “morning sickness,” which unfortunately may defy its name by lasting all day. Morning sickness can have bizarre triggers, so if yours is severe, you may want to take note of these to avoid them.

Many moms will feel nausea triggered by certain smells or activities, like riding in the car or standing in the shower. However, some may find that bright lights or even a specific song or type of music, spur a round of nausea.

If your sickness becomes severe enough that you are unable to keep down foods and nourish your body (and by extension, your baby’s) speak to your doctor about medications or other methods to control it.

Fatigue is often the first sign of pregnancy, showing up even before you’re aware that your period is late. Another contender for the first early warning sign is breast tenderness and swelling.

Though your baby weighs less than 1/20th of an ounce, some women will need to size up already in pants or loosen their clothing since the hormonal changes can set off bloating and gas.

Some women will have pain or cramping as the embryo implants into the uterine lining, and some will even have light spotting or implantation bleeding. However, continued cramping, more serious pain, or ongoing bleeding could be a sign of ectopic pregnancy, which requires emergency medical intervention.

You may have cravings, and they may be as bizarre as the stereotypical “pickles and ice cream” that find their way into pregnancy jokes. Many (though not all) of these cravings can be your body’s way of begging you for specific nutrients, so you may want to take a moment to interpret them. A possible sign you lack certain nutrients is cravings for foods that are not typical for you to eat or are unsafe. For example, if you crave raw hamburgers, it’s not because your body needs to eat unsafe raw meat; it may be your body crying out for iron or vitamin B12. You should satisfy these needs with safe foods, like cooked meats.

Some women crave nonfood substances, like dirt, sand, or chalk. You may crave ice. This can indicate a nutrient deficiency, usually iron or zinc. Satisfy your body’s needs with safe and healthy sources of these nutrients, including multivitamins and foods like red meat, spinach, broccoli, peas, and oranges, among other options. If you cannot resist eating nonfood items, speak to your doctor, as this can risk your and your baby’s health.

4 Week Pregnancy Symptoms Quick Recap:

• Many moms begin to experience early pregnancy symptoms, though not all will.
• Morning sickness can occur at any time of day and may have unusual triggers.
• If nausea is severe and prevents you from keeping food down, consult a doctor.
• Fatigue is often one of the first signs of pregnancy, even before a missed period.
• Breast tenderness and swelling may also appear early on.
• Hormonal changes can cause bloating and gas, leading some women to need looser clothing.
• Implantation cramping or light spotting is common, but severe pain or ongoing bleeding could indicate an ectopic pregnancy, which requires urgent medical attention.
• Cravings may develop and can sometimes signal a nutrient deficiency.
• Craving unsafe foods (e.g., raw meat) may indicate a need for iron or vitamin B12.
• Some women experience pica, craving nonfood items like dirt, sand, or ice, which may indicate a zinc or iron deficiency—consult a doctor if this occurs.

When To Contact Your Doctor

If you’ve had a positive pregnancy test, it’s time to contact an obstetrician. Your first appointment may still be two weeks or even a month or two away, but since practices can be booked several months out, it’s better to call earlier.

You should also call a doctor if you have cramping that doesn’t go away, pain that is not relieved with over-the-counter medications, or bleeding that seems heavier than spotting and doesn’t pass within a few days. About 1 in 4 people will have implantation bleeding; this should not be enough to soak a pad. According to the Cleveland Clinic, it may be a single bleeding incident or last a few days.

Severe pain can be a sign of an ectopic pregnancy and warrants contact with your doctor or emergency services.

Nausea or vomiting so severe that you are unable to keep down liquids can result in dehydration. If this continues and you are not passing urine, contact your doctor to determine whether anti-nausea meds will be sufficient or whether you should seek emergency care. Dehydration may require IV fluids as treatment. This could also be a sign of Hyperemesis Gravidarum, the most severe form of morning sickness experienced by around 3% of pregnant women.

Quick Recap Of What Mom Should Be Doing At 4 Weeks Pregnant:

• If you’ve had a positive pregnancy test, schedule an appointment with an obstetrician.
• Contact a doctor if you experience persistent cramping, pain not relieved by medication or heavy bleeding.
• Implantation bleeding occurs in about 1 in 4 pregnancies and should be light, not enough to soak a pad, and last only a few days.
• Severe pain can indicate an ectopic pregnancy, which requires immediate medical attention.
• If nausea or vomiting prevents you from keeping down liquids, leading to dehydration or lack of urination, consult a doctor.
• Hyperemesis Gravidarum is a severe form of morning sickness affecting about 3% of pregnant women and may require medical treatment, including IV fluids.

What Should Mom Be Doing At 4 Weeks?

Your main jobs right now are to get plenty of rest, provide your body with the nutrients it needs to grow a developing human, and generally take care of yourself.

You may want to start taking a prenatal vitamin.

If you haven’t chosen a doctor yet, it’s time. You can check with your insurance plan to see what providers are covered, speak to friends about their experiences with local obstetricians, or check reviews online. You’ll also need to check with providers to find out who is currently accepting new patients.

Avoid alcohol, tobacco, and illicit substances. Check with your doctor to find out if the prescription meds you’re currently taking are safe during pregnancy or whether you need to switch meds or be weaned off any. If you need help quitting any substance, be honest with your doctor about it.

The Big Debate: Do We Tell Everyone, Or Wait?

You have a positive pregnancy test. Is it time to make a Facebook post, tell your employer, and text extended family, or wait?

Traditionally, newly pregnant women have been advised to hold off on announcements, in part because of the risk of miscarriage and the pain of having to rescind that announcement or running into well-meaning folks in the grocery store who will ask you when you’re due while you’re mourning a loss.

Now, many people announce earlier, in part for the sake of gathering support during a period that can include struggling with nausea and other symptoms. Announcing early can help explain to your friend why you can’t sit next to her while she eats that dish with the pungent smell, or why you don’t want to be offered an alcoholic beverage at a party.

Some women will tell their employer reasonably early in pregnancy, especially if it may impact their work. Others would rather wait for an ultrasound confirmation that the baby is implanted in the uterus and growing properly before telling anyone.

Ultimately, each person will make her own decision, but all these factors may be a part of it.

What To Look Forward To

In the coming weeks, you’ll have your first prenatal appointment. Your doctor will schedule an ultrasound and may give you other instructions for caring for yourself and your pregnancy.

If you haven’t yet started to see physical symptoms of pregnancy, you can expect them to show up soon, a solid confirmation of your baby.

Now is the time to consider whether you’re interested in keepsakes, like a 4D ultrasound or a pregnancy photoshoot, and schedule these in advance.