3 weeks pregnant and earlier

The early days and weeks of pregnancy are the start of an exciting journey, but in the first few weeks you may not even suspect that you’re pregnant. In the first, second and third weeks you might not be experiencing any of the symptoms of pregnancy yet, but there’s already a lot going on. Read on to learn more about what happens inside your belly in the first few weeks, the early symptoms of pregnancy, how to calculate your due date, and much more.

What Happens in Your Belly at 1, 2 and 3 Weeks Pregnant?

If you have a typical 28-day menstrual cycle, at least one of your ovaries will release an egg around 14 days after the first day of your last period.

Keep in mind that this can vary depending on the actual length of your menstrual cycle. Once released, the egg will start moving down one of your fallopian tubes, where it may be united with sperm in a process called fertilisation.

Sperm can live inside your body for up to 7 days, and your egg has a lifespan of around 12 to 24 hours, so you can still get pregnant even if you don’t have sex precisely on the day of ovulation.

But what actually happens in the first few weeks of pregnancy? Keep reading to find out.

1 Week Pregnant

It may be a little hard to get your head round at first, but when you’re one and two weeks pregnant, technically speaking you aren’t actually pregnant yet. The reason for this is that the due date for your pregnancy is calculated from the first day of your last menstrual period (often referred to as ‘LMP’) before you conceive. Following this logic, when you’re one week pregnant, you’ve only just started your period. This explains why you may not experience any symptoms at this point. This means that, although your egg hasn’t been fertilised yet, if you do get pregnant this week, it will count as the first week of your pregnancy.

2 Weeks Pregnant

At two weeks pregnant your period may be over, and one of your ovaries is preparing to release an egg on its journey down one of the fallopian tubes leading from your ovaries to the uterus. This marks the start of ovulation, which happens 14 days after the start of your period (assuming you have a 28-day cycle).

Toward the end of this week, the egg travels down the fallopian tube and meets sperm somewhere in the fallopian tube. Once conception happens, things start to get very busy in your uterus…

3 Weeks Pregnant

At three weeks pregnant, you may not have any noticeable symptoms of pregnancy yet, but inside your belly is a hive of activity.

When your egg is fertilised by a sperm, they fuse together in the fallopian tube to form a single cell called a zygote. The zygote carries chromosomes from the mother and father, and these are the building blocks of your little one’s genetic makeup.

The zygote immediately starts dividing, constantly doubling the number of cells.

This cluster of cells continues its journey along the fallopian tube for another three or four days, constantly doubling in size, until it reaches the uterus.

Once there, it attaches to the lining of your uterus, in a process called implantation. Congratulations, you’re now pregnant!

In Summary

Due to the way due dates are calculated, you aren’t actually pregnant during the first weeks of a typical 40-week pregnancy! This stems from the fact that pregnancy is usually calculated starting from the first day of your last menstrual cycle. If you have a standard 28-day cycle, you won’t ovulate until your third week of pregnancy. In addition, you may also experience some light implantation bleeding, which is often easy to mistake for a period.


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Will You Notice Any Pregnancy Symptoms During Weeks 1, 2, or 3?

During weeks one, two, or three, you may not even suspect you’re pregnant and you might not notice any pregnancy symptoms at all, as it’s still very early. This is completely normal. Remember you might not have even conceived until 3 weeks pregnant. Often the first clue that you may be pregnant is a missed period; but keep in mind that this isn’t the most reliable indicator, especially if you don’t have a regular, 28-day menstrual cycle.

To make it even harder to tell, some mums-to-be can experience some very light bleeding after they conceive. Light spotting or bleeding may be caused by implantation, when the embryo buries itself into the lining of your uterus. This light spotting is often called implantation bleeding. It’s possible to mistake implantation bleeding for a light period, particularly as it can come around just when you might be expecting your next period anyway. It usually happens 10 to 14 days after conception. Other signs of pregnancy in the first month can include • bloating • gas • fatigue • breast tenderness • moodiness • frequent urination. Morning sickness is another common symptom of early pregnancy, but it usually crops up between weeks 4 and 9.

In Summary

You may not notice them at all, but there are several common signs of pregnancy that may occur during your first month of pregnancy. They include a missed period, implantation bleeding (light spotting), bloating, gas, fatigue, breast tenderness, moodiness, and frequent urination.

When Will You Be Able to Confirm That You’re Pregnant?

Home pregnancy tests are usually only effective after the first day of a missed period. However, there are some more sensitive ones on the market that claim to detect changes in your hormone levels a little before that – perhaps even as early as eight days after you conceive.

Pregnancy tests work by testing for the level of a pregnancy hormone called human chorionic gonadotrophin (hCG), which your body starts to produce around six days after fertilisation.

Remember, in the first two weeks of your pregnancy, you are not actually pregnant yet, and in the third week, your hCG levels may still be too low for most pregnancy tests to detect.

You can buy a home pregnancy testing kit at your nearest pharmacy or even some supermarkets. A pregnancy test can also be performed by your GP or at a sexual health clinic.

Keep in mind that while positive tests are almost always correct, a negative result may not be so reliable. If you think you may be pregnant, but the test says otherwise, try again after a few more days or speak to your doctor.

When Will Your Baby Be Born?

One of the first things you’ll probably want to know when you find out that you’re pregnant is how far along you are and when you’ll finally get to meet your little one.

Pregnancy usually lasts for between 37 and 42 weeks, counted from the first day of your last period, but your ‘due date’ falls at the end of 40 weeks. Doctors typically use the LMP method to determine your estimate due date. Keep in mind that if you use this method to calculate your due date, you aren’t technically pregnant during the first couple of weeks of pregnancy.

You can use our due date calculator to work out when that is, but keep in mind that it’s actually quite unusual for a baby to be born precisely on the due date.

For most mums-to-be, labour starts within a week or two either side of the due date.

How Far Along Am I?

Knowing how far along you are in your pregnancy is useful both for you and for your doctor and midwife, who will use this information to track you and your little one’s health and development.

The weeks of pregnancy are also divided up into three main stages, known as ‘trimesters’:

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:

How Far Along Am I?

What Precautions Should You Take During the First Few Weeks of Pregnancy?

If you’re trying to get pregnant or if you suspect you may be in the first few weeks of pregnancy, there might be some healthy lifestyle changes you could make.

Exercise & Diet

Maintaining your existing levels of physical activity (or starting on a new exercise routine if you think you aren’t getting enough exercise), can make it easier for your body to adapt to the physical changes you’ll experience during pregnancy and afterwards.

Read more about how to stay in shape while you’re pregnant.

Your doctor or midwife can also advise you if you’re unsure about how to exercise safely during your pregnancy.

Eating healthily when you’re pregnant is also an important way of giving your little one the best possible start in life.

Eating nutritious and healthy foods, like lots of vegetables, fruits, fibre-rich foods and protein will help your little one develop and grow properly.

It’s also a good idea to eliminate some less healthy habits like smoking, exposure to second-hand smoke and drinking alcohol. Your doctor may also suggest limiting your daily consumption of caffeine. We recommend talking to your doctor to find out the best ways to stay healthy and safe when pregnant.

For more on this topic, read up on what not to eat when pregnant.

Vitamins and Supplements

These are some of the vitamins and supplements your doctor may recommend you take as soon as you find out you’re pregnant, or even when you start trying to conceive:

  • Folic acid. Folic acid lowers the risk of problems with your little one’s development in the early stages of pregnancy. A supplement of 400 micrograms of folic acid a day is recommended from when you start trying to conceive, until you’re 12 weeks pregnant.

  • Vitamin D. This vitamin has a key role in regulating your calcium and phosphate levels, which are important for the health of bones, muscles and teeth. Vitamin D levels may be lower in the winter, and if you have dark skin you may also have a higher risk of vitamin D deficiency. Ask your doctor or midwife whether you could benefit from taking vitamin D supplements.

  • Iron and calcium. Low levels of iron in your body can make you tired, and possibly anaemic. Good sources of iron in your diet can include lean meat, dried fruit and nuts, and green leafy vegetables. Breakfast cereals may also contain added iron. If the concentration of iron in your blood is low, your doctor or midwife will recommend iron supplements for you. Getting enough calcium, meanwhile, is important for building strong teeth, muscles and bones. You can up your calcium intake by eating plenty of dairy, such as milk and yoghurt, fish that can be eaten whole with the bones, and green leafy vegetables like rocket or watercress.

  • Vitamin C. You can usually get all the vitamin C you need to protect cells and keep them healthy by eating a balanced diet with plenty of fruit and vegetables. In some cases, however, your doctor may recommend supplementing your diet with a vitamin C tablet. If you take vitamins in the form of a combined ‘multivitamin’ tablet, make sure it doesn’t contain vitamin A (retinol), which could harm your little one. Always ask your doctor before taking a vitamin or dietary supplement during your pregnancy.

The Bottom Line

Outwardly, it might look like not much is happening yet in weeks one, two and three of pregnancy, but this is just the start of a great adventure for you and your growing family. Inside, a flurry of activity is taking place and by the end of these first few weeks the first building blocks of your baby will be in place. Perhaps even unbeknownst to you, you’re at the start of a wonderful journey. Sign up below for regular updates on what happens in each week of pregnancy:

How We Wrote This Article
The information in this article is based on the expert advice found in trusted medical and government sources, such as the National Health Service (NHS). You can find a full list of sources used for this article below. The content on this page should not replace professional medical advice. Always consult medical professionals for full diagnosis and treatment.