What Are The Signs of Pregnancy in the First Week?

Did you know that pregnancy symptoms can start right at the beginning, before you‘ve missed a period? Even when your baby is just a tiny ball of cells, the changes in your hormone levels can have a big effect on your body.

Signs of Pregnancy

When Does the First Week Begin?

You may find the way that we date pregnancies a little bit odd. We usually start counting from the first day of your last period. When your midwife or sonographer talks about how many weeks pregnant you are, they will usually be counting from this day. The reason we do this is that your period is much easier to date than the actual conception. You can always tell when your period arrives, but unless you’re tracking your ovulation you probably don’t know exactly when it happens.

Conception happens around the time that you ovulate, but we don’t usually know exactly when it occurred because:

  • Most women ovulate (release a mature egg) at around day 14 of your menstrual cycle (day 1 is the first day of your period). We don’t always know when it happens as there aren’t any obvious signs.
  • Sperm can survive inside your body for about a week, so you can get pregnant if you have sex before you ovulate.
  • The egg will be available for fertilisation for about 24 hours, so you can get pregnant if you have sex on the day after you ovulate.
  • It takes between 45 minutes and 12 hours for sperm to reach the fallopian tubes (where the egg is waiting) after it has entered your body.

What all this means is that there is a 24 hour period when fertilisation can happen, but that you can have sex up to a week before this and still get pregnant. You can’t tell exactly when the egg and sperm will meet and you might not even know which day you are ovulating on. Since it’s so difficult to know when you actually conceived, no one is going to expect you to be able to tell them. Instead, your midwife or doctor will ask when your last period started. It gives us an easy date to use as the start of your pregnancy.

What makes this a little strange is that you aren’t actually pregnant at this time. Periods are a pretty obvious sign that you’re not carrying a baby. You won’t be able to conceive until you ovulate, which usually happens about 10-15 days later, depending on the length of your menstrual cycle. However, it’s much more convenient to date your pregnancy from the last period. You just have an extra two weeks that count as pregnancy before you actually get pregnant.

You will get a more accurate date for your pregnancy after your first ultrasound scan. Babies develop at a very similar rate in the early weeks, so we can tell how long you’ve been pregnant from the size and development of your baby. However, we’ll probably still use the traditional approach when talking about how long you’ve been pregnant. We’ll tell you that you’re 12 weeks pregnant even though the actual conception happened during week 2.

What Happens During the Real First Week of Pregnancy?

Clearly, you’re not going to experience any symptoms during the first two weeks that we count as the start of your pregnancy. However, you could start noticing some changes as soon as you actually conceive. What will happen during the first week after conception?

Your Baby’s Development

Baby has a lot of work to do during the first days after conception. When the egg is fertilised, it is still sitting in the fallopian tube. It has to make its way along this tube and into the womb, where it must implant itself in the endometrial lining in order to survive. The embryo is already growing and dividing to create new cells. Some of the cells will develop into the placenta that will feed and support the baby. Others will go on to form your baby, or in the case of identical twins, they could even end up as more than one.

Pregnancy Symptoms Before You Miss a Period

The most obvious sign that you might be pregnant is a missed period, but your period won’t even be due until a couple of weeks after you conceive. During this time, you might already notice some pregnancy symptoms. Even though your baby is just a tiny ball of cells, your body is already preparing for what is to come. The hormones that would usually start to decline at the end of your cycle will instead remain high so that your womb lining stays thick and healthy. It is these pregnancy hormones that are responsible for your early symptoms. They are already starting to prepare your body for the coming months.

Possible signs of pregnancy during the first week after conception include:

  • Sore or tender breasts, sometimes with darker areolas
  • More sensitive to certain smells
  • Light spotting or bleeding, which can be a sign that the embryo has implanted itself
  • Needing to pee more often
  • Feeling more tired than usual
  • Nausea
  • Bloating

These early signs of pregnancy aren’t easy to spot. In fact, they can be very easy to miss because they are so similar to pre-menstrual symptoms. You might just think that your period is coming. Even if you’re trying to get pregnant and you know exactly when you ovulated, you might still miss these signs or think that they’re due to your period. It can be a bit of a surprise to find out that you’re actually pregnant when you’ve just been thinking you’ll have to try again next month.

When Can You Find Out for Sure?

The earliest pregnancy tests can be taken about 6-7 days after ovulation. If you know when you were ovulating then you can take these tests about a week later. They can also be useful if you’re experiencing possible signs of pregnancy and you want to be sure. However, it’s usually better to wait until after you’ve missed a period before you try a pregnancy test as the results can be more accurate. It’s also important to check the instructions on the packet as some pregnancy tests won’t work this early.

How soon did you suspect you were pregnant?

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