1 Week Pregnant

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1 Week Pregnant

Becoming pregnant can be a daunting experience. It is difficult to know how soon you can tell if you’re pregnant, but many women display pregnancy symptoms as early as the first few weeks after conception.


It is important to remember that although you are medically described as pregnant at week 1, you are not yet pregnant. This is because, for calculation purposes, medical practitioners calculate the start of your pregnancy from the first day of your last menstrual cycle. Therefore, any first signs of pregnancy symptoms that you think you are displaying at 1 week pregnant are the symptoms that you will typically experience during your period – you will not start showing any signs of pregnancy until conception occurs.

Yet, the clock starts ticking from the first day of your last period. There are many ways you can detect early pregnancy symptoms and this article aims to help you identify what pregnancy signs in week 1 you should and shouldn’t look out for. This is the first in a series of pregnancy progression articles that will guide you through the week by week pregnancy process.

Early Signs of Pregnancy

It’s probable that you aren’t displaying any early signs of pregnancy when you are 1 week pregnant, as you technically aren’t pregnant yet. Many women don’t show any symptoms until week 4 or 5 of the pregnancy cycle. That being said, to detect pregnancy symptoms you should look out for the usual menstruation cycle symptoms that your body experiences. These can be very early signs of pregnancy that help you figure out how to tell if you’re pregnant or not.

1 Week Pregnant Symptoms

You might have asked yourself the question, “can you feel the effects of pregnancy early?”, and it’s difficult to answer this, as you are not technically pregnant at week 1. Different women experience different symptoms of pregnancy, and there are a number of pregnancy symptoms from day 1 of conception that you might display. Here are some common signs and symptoms of pregnancy that you may find:

  • Bloating
    A symptom that you may also experience during your period. The fluctuation in hormone levels can lead to the bloating of the belly.
  • Headaches
    Changes in hormone levels can also lead to intense headaches, or menstrual migraines.
  • Vaginal bleeding
    Slight bleeding can occur due to the shedding of the uterine lining.
  • Back pain and cramps
    When your body releases the uterine lining, contractions in your uterus occur. This can lead to lead to uncomfortable cramps and pain in your lower back and/or abdomen region.
  • Mood swings
    Another side effect of fluctuating hormones is the rapid change in your mood, which can lead to irritability and an unstable emotional state.
  • Tender or swollen breasts
    One of the first symptoms of pregnancy could be tenderness in your breasts, or a noticeable difference in their fullness due to hormonal changes.

Your Body at Week 1

Many things will be happening to your body when you’re 1 week pregnant. You will be having your last menstrual period for a while, and the start of your pregnancy cycle has begun. The follicle stimulating hormones (FSH), each containing an egg, battle to become dominant, with the winner going on to ovulate. As FSH matures, estrogen is produced, leading to a surge in the production of luteinizing hormone (LH). LH is what causes ovulation, allowing the egg to travel through the ovarian wall to be fertilized by the sperm.

Another likely early pregnancy symptom that occurs to your body at week 1 is the fluctuation in your basal body temperature (BBT). When you ovulate, your BBT will decrease to its lowest point, before rapidly increasing by around half a degree. This fluctuation in temperature can be noticeable and is one of the very early signs of pregnancy that you will feel in your body.

Increases in cervical mucus is another one of the early symptoms of pregnancy that can have a noticeable impact on your body at week 1. As you get closer to conception, cervical mucus will increase in volume and have a cloudy appearance.

early signs of pregnancy

Image by Sarah Richter from Pixabay

Baby Size at Week 1

If you notice an increase in the size of your abdomen region, it is not related to the baby size at week 1. More likely, you will be experiencing bloating due to the volatile fluctuations in hormone levels. Even by week 4 of pregnancy, your fertilized egg, or zygote, is only the size of a poppy seed. Week 1 and week 2 of pregnancy are when you’re not considered truly pregnant (because conception hasn’t yet occurred), so the baby size is non existent at this point.

Week 1 Pregnant Ultrasound

Despite what you might think are some early pregnancy signs in week 1, there will be no ultrasound image of your baby at this stage. The earliest sign of pregnancy using an ultrasound can usually be detected by weeks 4 or 5, when a gestational sac can be seen. It is common, though, for ultrasounds not to be performed until the 6th week of pregnancy, and here is when you can start to see the rapid changes in baby size week by week.


Despite the possibility of showing some symptoms during the first week of pregnancy, most women don’t experience morning sickness until weeks 5 or 6. This usually lasts until weeks 12 or 14, though some people experience morning sickness until as late as week 20. Yet, some women don’t experience any morning sickness or discomfort.

You can’t tell if you’re pregnant in week 1. There are some obvious and less obvious early signs and symptoms of pregnancy after conception. The most common early pregnancy signs are missed periods, increased urination, fatigue, tender breasts, and nausea.

Apart from the signs you’re pregnant outlined above, it’s not possible to know when you conceived using a pregnancy test during week 1. Most pregnancy tests should be taken after the first day of your missed period.  After taking a pregnancy test, a positive result is almost certain to be reliable, whereas a negative test is less reliable, and you may have to take another one to be sure.


Pregnancy symptoms can start as early as week 1. Even though you are not technically pregnant in week 1, the cycle starts on the first day after your last menstrual cycle. This means that the early pregnancy symptoms that you experience in the first week of pregnancy will be similar to the symptoms that you are experience when you are on your period.


It is usually not common to feel the effects of pregnancy in week 1, and most women start to show early pregnancy signs around 1-2, when they will start to show conception symptoms. Tender breasts, fatigue, and mild nausea are likely to be experienced at this stage.

By Editorial Team

NetParents is the go-to resource for all parenting issues. We are an independent body that seeks to offer general information on various parenting topics and unbiased reviews on baby products.

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