If you’re one of those moms who didn’t exactly expect to get pregnant, this is right around the time you will probably suspect that those odd symptoms you’ve experienced over the past few weeks might be pregnancy related—especially after you miss your first period.

If this sounds like you, and you’ve had a positive pregnancy test, it can be tempting to panic, thinking, “But I’ve still had an occasional drink, and I’m not eating all that great! Have I hurt my baby?” The quick answer is not to worry—you can start doing all the right things now. Still, if you’re just finding out, this is a good time to call and set up a prenatal appointment with your doctor or midwife.

Alternatively, if you already know you’re pregnant because you’ve been testing since ovulation, congratulations on your first full month as a mom-to-be!

Your Body

your pregnancy week 4

At this point in your pregnancy, it’s still too early to be “showing,” but that doesn’t mean your body isn’t undergoing dramatic changes. Your hormone levels are already changing as estrogen and progesterone levels drastically rise, which is necessary to facilitate the many changes your body needs to go through to grow a baby.

It’s important at this stage to take good care of yourself (just like always!). Pay careful attention to your diet, and try to eat a healthy diet based on whole grains, fruits, and vegetables. It’s likely too early in your pregnancy to experience the ravenous hunger you hear many moms talk about, but that is no excuse to go on a strict diet. Weight gain during pregnancy is normal and healthy—a woman of average weight should gain about 25-35 pounds during pregnancy. A woman of below average weight should aim to gain between 28 and 40 pounds, while for an overweight woman, that number is 11-25 pounds, depending on her body mass index.

What does this mean in terms of calories? Although this will differ for every mom, it’s suggested that you will add about 300 calories to your daily diet to support your growing baby. Remember, however, that these should be healthy calories—so adding 300 calories of daily ice cream is not recommended!

Otherwise, you should continue your exercise program, avoid alcohol and drugs, and keep your obstetrician or midwife apprised of any prescription or over-the-counter drugs you take. Certain drugs have been shown to have an adverse effect on your baby or your body during pregnancy, so now is the time to run it past your provider if you haven’t already done so. In terms of supplementation, continue to take your prenatal vitamin, which includes many healthy nutrients, especially the very important folic acid. 

Your Baby


The fetal age of your baby now is 2 weeks, and the size ranges anywhere from about 0.014 inch to about 0.04 inch, or about 1 mm in length—roughly the size of a large grain of sand.

Still called a blastocyst, the developing fetus is deeply embedded in the uterine wall, and the amniotic sac that will later protect your baby during gestation is beginning to form. At the same time, the uterine wall is thickening and forming the placenta, which will deliver nutrients and oxygen to your baby via the umbilical cord throughout your pregnancy. As the placenta grows, your blood volume will increase in the coming weeks.

Despite the embryo’s young age, specialized cells are already starting to form that will later make up organs, skin, and other structures. This includes the early brain and spinal cord, which are already beginning to form. In addition, the developing blastocyst is forming three “germ layers” that will each contribute different organs. The germ layers include:

  • Ectoderm: nervous system, brain, skin, and hair
  • Endoderm: gastrointestinal tract lining, liver, pancreas, and thyroid
  • Mesoderm: Skeleton, connective tissues, blood system, urogenital system, and muscles

Doctor Tip
“Some women wonder when they should tell others that they are pregnant. There is no right or wrong answer, so do whatever makes you and your partner comfortable.”

Read more doctor tips.

Reviewed by Dr. Jen Lincoln, November 2018


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