01-03 Weeks Pregnant Baby Size

Pregnancy begins on a beautiful journey where you might not even know you are pregnant. You may not notice any signs and symptoms of pregnancy in your first three weeks. This is because there is a lot that will be happening in your womb. Keep reading to know more about the transformation, symptoms of pregnancy in the first month, how to calculate your due date, and how far along you are in your pregnancy.

What Happens in the First Three Weeks of Pregnancy?

An average menstrual cycle is of 28 days. During this cycle, around 14 days after the first day of your last period, one of your ovaries releases an egg. This egg moves down to one of your fallopian tubes, where it might get united with a sperm. Your egg has a lifespan of up to one day, whereas sperm can live inside your body for up to five days. Due to this, your window of fertility is about five days before ovulation to a day after.

Here is a small guide to understanding what happens from before conception and onward:

1 Week Pregnant

Although your journey through pregnancy begins now, technically, you’re not technically pregnant. Doctors usually calculate the length of pregnancy as 40 weeks from the first date of your last period. However, as mentioned earlier, since ovulation happens around 14 days, probably conception takes place during this time.

Hence, the doctor considers this week and the next week as a part of your pregnancy, even if you haven’t conceived just yet. We understand that it might come as a surprise to you, but you are not really pregnant in your first week.

2 Weeks Pregnant

At 2 weeks pregnant, your period might be over, and ovulation might be just days away. At the end of this week, if you have intercourse successfully, conception will take place when the egg and sperm meet. Once this happens, your uterus will become a very busy place.

3 Weeks Pregnant

By 3 weeks pregnant, numerous activities will take place in your belly, which you may not even notice or feel. The sperm and egg join up in the fallopian tube, where a single cell called a zygote is created. This process is called fertilization.

The zygote carries chromosomes from you and your partner, setting the first building blocks of your future baby’s genetic development. The zygote moves down the fallopian tube towards the uterus as it starts dividing into a larger group of cells.

Are There Any Visible Pregnancy Symptoms During Weeks 1, 2, or 3?

During the first three weeks, you may not even know about your pregnancy, and you might not even notice any early pregnancy symptoms at all. Ideally, the first cue of you being pregnant would be missing a period. During this time, or maybe a little later, you might start noticing some of the symptoms. A few subtle changes can hint towards pregnancy, and some women are quick to sense and recognize them.

Some of the most common early pregnancy signs include:

Implantation bleeding or spotting

It is called implantation bleeding because it occurs when the fertilized egg implants in the uterus. Your baby is developed into a tiny ball of cells, called a blastocyst. This tiny ball contains hundreds of cells that are multiplying and attaching to the uterus lining. This might result in some light spotting which is very normal. It can sometimes be mistaken for period spotting as it can come around just when you are expecting your next period anyway.

Bloating and cramping

Your body releases progesterone that will relax the muscle throughout your body. As this hormone relaxes your digestive tract, it slows down digestion, leading to gas and bloating. This may create uncomfortable sensations in your stomach, leading to cramps.

Breast tenderness

The breasts might become sore and more tender than they are before a period.

Changes in the basal body temperature

If you usually keep a tab on your basal body temperature, you will notice that is slightly higher than earlier this week.

Other symptoms of pregnancy in the first month can include moodiness, frequent urination and food aversions. However, these are subtle changes that you might often miss noticing. Another common sign is morning sickness, but it might usually start somewhere around weeks 4 to 9.

How Can I Confirm My Pregnancy?

If your period is quite regular, missing it will be your first clue. If you think you might be pregnant, you can take a home pregnancy test. These tests usually check for the presence of pregnancy hormones called human chorionic gonadotrophin (hCG) in the urine. However, taking the test too early may give you false negative or accurate results. There may not be enough hCG in your urine yet, as these pregnancy hormones are pumped out by the placenta around six days after fertilisation. Once the hCG levels increase in your urine, the test will give you a positive result.

It is best to always read the information on the packaging of pregnancy tests before taking the test. This is because some tests require you to wait until the first day of your missed period as they might not detect low levels of hCG. These home pregnancy tests are only effective then. There are also some sensitive tests in the market that can detect even low levels of the hormone even as early as eight days before conception. Hence, they can give you an accurate result a little early.

Sometimes, negative test results are not so reliable, especially if you take the test incorrectly. If you still feel you are pregnant, you can always take another test after a few more days. You can also consult your general physician or your gynaecologist to get yourself checked. Your doctor might recommend a blood test to confirm your pregnancy.

How Do I Calculate My Due Date?

Once your pregnancy is confirmed, the first thought that excites you will be, “when does my baby arrive?” You can try our Due Date Calculator for an estimate. In this pregnancy calculator, you have to simply input the first day of your last period or the date of your conception.

Remember, only a few babies are born exactly on their due date, and it is totally normal if the birth date changes by two weeks before or after your due date. For an accurate estimate of your due date, talk to your doctor. Usually, due dates are calculated as 40 weeks from the first day of your last period. So, when calculating your due date, your first week of pregnancy is actually the week you had your last period when you were not pregnant yet. As mentioned earlier, we totally get you - it’s a little difficult to wrap your head around, but based on the method of due date calculation, you have not yet conceived in the first couple weeks of the 40 weeks of pregnancy.

How Far Along Am I?

It is useful for you as well as your doctor to know how far along you are in your pregnancy. Knowing this information will help your doctor to check on your baby’s growth and development. Moreover, your doctor can keep an eye on your health, and also schedule tests and exams accordingly.

Keep a note of your weeks of pregnancy which are also grouped into three trimesters:

  • First trimester (Week 0 to Week 13): It is roughly one to three months

  • Second trimester (Week 14 to Week 27): It starts from the fourth month and goes up to the seventh

  • Third trimester (Week 28 to Week 40): It starts from the seventh month and goes up to the ninth

So that you can see at a glance how far along you are in your pregnancy, and which trimester you are in, check out the illustration below:

Week by Week Pregnancy Chart

What Precautions Should I Take While Trying to Conceive and During Early Pregnancy?

If you’re trying to conceive, there are some lifestyle changes you might need to make. Now you won’t be aware of your pregnancy until the first few weeks, so it is best to take some precautions as soon as you start trying. These precautions you can then continue further during your pregnancy.

One of the basic yet most important habits you need to focus on is eating healthy food and exercising regularly. You can also consult your doctor, and he may recommend you start taking folic acid as you start trying for a baby. If you’re wondering about folic acid, then it is a type of vitamin B that helps reduce the risk of certain birth defects in the brain and spine of a baby. Your doctor will accordingly recommend a prenatal vitamin that contains around 400 micrograms of folic acid, which is the required amount.

Trying for pregnancy is also the best time to get rid of some of your less healthy habits. You need to quit smoking and drinking alcohol. Sometimes, your doctor may also advise you to limit your caffeine intake. If your partner is a smoker, he or she has to quit too, as second-hand smoke can be harmful to you and your baby.

The Big Picture

Although it might seem like there is not a lot going on during your first three of pregnancy, it is still an eventful time for you and your growing family. Inside your belly, there is a hive of activity taking place, and by the end of these first few weeks, the initial building blocks of your baby will begin. Perhaps, even if you aren’t aware, you’re at the beginning of a beautiful journey!