Week 4 Pregnancy: Symptoms & Early Signs of Pregnancy

Katie GriffinOnline Childbirth Classes for Natural Birth, Pregnancy

Week 4 Pregnancy - Symptoms and Early Signs of Pregnancy

You’ve likely just found out that you’re expecting!  With the nerves and adrenaline rush of a positive pregnancy test, your life has officially changed forever.  Congratulations!  You are a mama-to-be!  At 4 weeks pregnant–just 2 weeks out from conception–your body is at the start of an amazing journey to parenthood. Kopa Birth® is honored to share this experience with you!

Before we jump into week 4 of your pregnancy, let’s briefly recap what you missed in the weeks before you found out you were pregnant.

Week 1 Pregnancy

This was the first day of your last menstrual cycle.  You weren’t actually pregnant yet.

Week 2 Pregnancy

You still weren’t pregnant at this point.  Your body was busy preparing the lining of the uterus for potential implantation.

Week 3 Pregnancy

This is the week in which you ovulated and had sex.  The sperm and your egg cell then met in the fallopian tube and conception occurred.  With time, the fertilized embryo (aka. the ball of cells that will become your baby) made its way to the uterus for implantation.

Week 4 Pregnancy:  How big is your baby?

Now you’ve arrived at week 4 of gestation.  Your baby is 2 weeks old (per the conception date) and is growing and changing rapidly!  He or she measures about 1mm in length.  For a frame of reference, one millimeter is half the size of the letter “o” on the page…the same size as a poppyseed.  That’s a teeny little ball o’ cells 🙂 (1)

Week 4 Pregnancy - How big is your baby

At week 4, your little one is about the size of a poppy seed. Don’t you worry…he or she will get a whole lot cuter in a couple months 😉

Week 4 Pregnancy:  Baby’s Development

Your baby’s cells are multiplying RAPIDLY.  At the same time, they’re starting to differentiate into the various functions they’ll take on as the body grows.  Liver cells, blood cells, and neurons all begin to form a distinct identity and purpose (2).

Other notable developmental milestones include:

  • Baby’s liver begins to function
  • Kidneys and heart are forming
  • Blood is beginning to circulate
  • The neural tube, which ultimately becomes the brain and spinal cord, is developing
  • Amniotic sac is forming

Week 4 Pregnancy - Baby Development

Week 4 Pregnancy:  Symptoms

You’re probably oblivious to most of the changes going on inside your body at this early stage in the pregnancy.  But you may notice some symptoms associated with implantation–the process in which the embryo burrows safe and snug into the nourishing uterine wall.

Week 4 pregnancy - Implantation bleeding

Implantation Bleeding

Tiny blood vessels in the uterine lining can get disrupted as the embryo implants there.  A very small amount of light bleeding can occur as a result.  This is normal and harmless.

The bleeding with be very light in color and flow — probably just a few drops of blood.   You may initially mistake it for the start of your menstrual period, however it won’t get heavier and dark in color like a typical period.

Week 4 Pregnancy:  Early Signs of Pregnancy

Some common early signs of pregnancy that you might experience at week 4 in your pregnancy include:

  • A missed menstrual period
  • Breast tenderness
  • Slight cramping or tenderness in the abdomen

Week 4 Pregnancy - Early Signs of Pregnancy

Week 4 Pregnancy Tip

Now is the time to take a hard look at your medicine cabinet.  Prescription and over-the-counter drugs that are normally safe can lead to birth defects or fetal harm when taken during pregnancy.  Discuss all medications with your health care provider.

Again, congratulations on your pregnancy!  Join us again in a few days to learn all about Week 5 of your pregnancy!

Kopa Birth’s online childbirth classes allow you to prepare for a natural childbirth from the comfort of your own home, 24/7. Enroll today in our free online childbirth class to learn more about preparing for a natural hospital birth.


(1) Glade, B.C., Schuler, J.  (2011).  Your Pregnancy Week by Week, 7th edition.  First Da Capo Press.

(2) Ladewig, P.A., London, M.L., Davidson, M.R.  (2006).  Contemporary Maternal-Newborn Nursing Care, 6th edition.  Pearson Prentice Hall.  Upper Saddle River, NJ.