4 Weeks Pregnant: Your Pregnancy Guide Week by Week (2018)


In the fourth week of pregnancy, 28 days have elapsed since the beginning of your last period. Fertilization has occurred, symptoms have become persistent, and there’s no longer any ambiguity about the pregnancy itself.

4 Weeks PregnantYour baby (still referred to as a blastocyst) has officially begun its foray into physical development. While still microscopic in size, the blastocyst will start forming a tiny face with barely formed eyes and nose within the next week.

At four weeks, your blastocyst is now also officially an embryo and has begun its foray into the embryonic stage. Very soon your babies various body parts and organs will begin their formations while the amniotic sac will rapidly begin to enshroud the embryo to safely and comfortably keep your baby secure during your pregnancy term.

It’s an exciting time for mothers-to-be. The psychological impact involved from discovering the fact that their fertilized egg has now started to take its beginning developments into human form is deeply profound. For many mothers, the pregnancy becomes very “real” at this point. Many women who found themselves still struggling to kick harmful habits like smoking and drinking often find themselves kicking the habits for good overnight after fully realizing how real things have become.

For some women, it takes the sight of their baby on an ultrasound to stun them into transformative action. For others, it might take the news from their doctor that their baby is now on theprecipice of developing a face with the beginnings of a nose and eyes. Many will have reached their own epiphany while in week three of pregnancy after discovering that the sperm and egg union resulted in a chromosomal human blueprint for their future babies.

Week four is an imperative time to crack down on maintaining good health and dietary habits. Folic acid should be taken daily in conjunction with vitamin D. With the blastocyst on the cusp of undergoing rapid physical development, the need for vitamin D becomes immediately important.

If you haven’t already, a visit with your doctor must be scheduled. Your doctor will go through a comprehensive list of questions to help guide you through and achieve a healthy and successfuldelivery. Many issues will be addressed including any mental health problems and corresponding medications along with the presence of sexually transmitted diseases that can severely impact a baby’s health.

Your doctor’s visit is an opportune time to bring up the most pressing questions that you have about your pregnancy. Be prepared by writing a list of your questions and concerns4 Weeks Pregnant and bring it with you to the appointment along with a pen and paper to take notes that you can review later.

Some important concerns you may want to address with your doctor at this initial appointment are any health issues that you have, prescription medications you consume, or previous pregnancy problems that could potentially impact the health of your baby.

Your Physical and Emotional Health: 4 Weeks Pregnant Symptoms

The symptoms listed in the chart below from week three may persist or even drastically increase.

More commonly, many women find the hCG pregnancy hormone to be particularly troublesome during this time in their pregnancy.

At an all-time high, hCG levels in the body can cause dizziness or vertigo-like symptoms, fainting, light-headedness, and extreme nausea in addition to the anxiety, frequent mood swings, irritability, and vomiting.

Many women will also report breasts that are painfully sore and tender to the touch in addition to a seemingly superhuman sense of smell that becomes so sharpened that even slightly foul odors can induce vomiting.

  • Changed or heightened sense of smell
  • Significant increase in breast tenderness with breasts feeling heavy and swollen
  • Increased fatigue or even exhaustion
  • Increased nausea
  • Sudden inability to tolerate the taste or smell of certain foods
  • Extreme increase in urinary frequency
  • Vomiting resulting from changed sense of smell
  • Sudden food cravings
  • Consistently high basal body temperature levels
  • Spotting/bleeding
  • Body soreness

Your Baby’s Health and Status: 4 Weeks Pregnant Baby

The fourth week of pregnancy heralds the official beginning of what’s called the embryonic period. Lasting from the fourth until the tenth week, the blastocyst will begin transforming into a baby with the development of functioning organs.

Still microscopic in size, your baby is a tiny ball of cells embedded comfortably in your uterus and undergoing rapid transformative measures that mark the beginning of a fast-paced six-week developmental chapter that will culminate in incredible results.

Tips, Tricks, and Knowledge at 4 Weeks Pregnant

  • By week four you should be including vitamin D in your supplement routine. Along with4 Weeks Pregnant 400 micrograms daily of folic acid, take vitamin D. Liquid vitamin D drops are best as they are the most bioavailable form for your body. Just a tiny drop or two once per day will take care of your vitamin D needs for you and your growing baby.
  • You may require higher dosage folic acid. At your initial visit with your doctor, have a conversation about folic acid supplementation and see what he or she recommends. Simple blood work can yield valuable information about the folic acid levels your body requires for optimal health.
  • Try to eat foods that are high in folate, such leafy green vegetables like kale and chard, berries, and beans.
  • Even if you eat many foods high in folate, continue supplementing with folic acid
  • Having enough folic acid is hugely important and prevents seriousbirth defects like spina bifida

To-do List and Reminders at 4 Weeks Pregnant

  • Verify your health insurance coverage and inquire about coverage for pregnancy, prenatal care, general maternity care in addition to the cost of pediatric visits to the doctor and immunization coverage for your baby. Learn as much as you can about your insurance policy, the copays and deductibles involved, and be prepared to change plans if you have to.
  • Consider your birthing strategy; are you more comfortable going to a hospital or perhaps giving birth at home with a midwife by your side?
  • Stock up on Folic acid and Vitamin D and remember to take them daily to ensure optimal health for your baby
  • Make an appointment with your doctor and come prepared with your questions and concerns (remember to bring a pen and paper for notes that you can refer back to later). Be prepared to answer a long list of questions that your doctor will ask about your diet, mental health, physical health, presence of diseases, and much more


Hypoblast: One of two layers of the embryo. Surrounds the epiblast layer to form what’s4 Weeks Pregnant called an embryonic disc that will eventually develop within the embryo itself

Epiblast: One of two layers of the embryo and also part of what will become the embryonic disc that will stretch connecting amniotic cavity and what is referred to as the yolk sac.

Embryonic stage: This is the stage that occurs right after the implantation happens and is when the major organs and body parts begin forming

Cool Things to Know

  • Your baby is now almost the size of a single poppy seed! Next week he or she will grow to the size of a sesame seed and begin forming a tiny little face and features
  • At this point, your baby is an embryo made up of two layers called the hypoblast and epiblast which are dually responsible for the development of your baby’s body and organs

Ready to find out what’s next in your pregnancy journey?

Click here for all the information you need to know about week 5 in pregnancy!


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