1st Week Pregnancy: Symptoms, Baby Development, Tips And Body Changes

1st Week Pregnancy

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You don’t even know you are pregnant. That’s how your first week of pregnancy goes because it is the week when your menstrual cycle occurs.

So are you pregnant in the first week? You may or may not be.

Momjunction explains what exactly happens in your body during the first week.

What Should You Know?

The usual length of a monthly cycle is 28 days. Accordingly, ovulation may happen between the 12th and 14th days of the cycle*. During ovulation, a mature egg is released from the follicle into the fallopian tube. The egg waits for the sperm to get fertilized (1). If the sperm does not meet the egg, then fertilization does not take place; the uterus sheds the endometrial lining that it has been weaving through the month, and your next period begins.

However, if the sperm meets the egg, and fertilization takes place, then you become pregnant.

* Note: The length of the menstrual cycle varies in women. Your time depends on the length of your cycle.

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Are You Really Pregnant In The First Week?

Practically speaking, you are not pregnant in your first week.

The first day of your last period is used to calculate the gestational period because it is not possible to find out the exact date of ovulation or conception.

[ Read: 2nd Week Pregnancy ]

After the periods are over, the cervix starts discharging mucus to enable the sperm swim smoothly through the cervix to the fallopian tube. If you want to get pregnant, you may count your ovulation time, and have sexual intercourse three days before and on the day of ovulation.

Click here to calculate your ovulation time.

The chances of getting pregnant in the first week are almost zero. However, you are likely to ovulate and get pregnant in the first week itself, if your menstrual cycle is short (21 days), and have early ovulation (around the seventh day).

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First Week Of Pregnancy: What Is Happening Inside The Body?

If ovulation happens in the first week, then the egg will travel to the fallopian tube. If it gets fertilized, conception occurs.

The cell division takes place over the next three days following fertilization. The cell structure formed during this week is called a blastocyte. Over the next two weeks, the outer layer of the blastocyte becomes the placenta and the inner layer turns into the embryo and gets attached to the uterine wall (2).

This process begins only after the first week.

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Does Your Body Show Any Pregnancy Signs And Symptoms?

As mentioned earlier, there is no way you would realize you are pregnant. There wouldn’t be any symptoms except those of your menstrual period, such as:

  • Bloating
  • Mood swings
  • A headache
  • Lower back pain and cramps
  • Fatigue
  • Breast tenderness

Just in case you suspect you are pregnant or hoping to get pregnant, begin to follow a healthy lifestyle.

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[ Read: 4th Week Pregnancy ]

Tips For The First Week Of Pregnancy

Here is what you can do:

  • Switch to a healthy lifestyle.
  • Avoid smoking, drinking, and excessive intake of caffeine.
  • Track the cycle to find your exact ovulation period.
  • Start taking folic acid supplements.
  • Add a lot of vegetables, fruits, grains, and pulses to your diet.
  • Stay calm and relaxed; keep stress at bay.
  • Keep exercising as it helps alleviate your mood, and energizes you.

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The first week of your menstrual cycle is considered the first week of pregnancy for the convenience of calculating your gestational length. This is a more practical way than relying on your ovulation or conception time. You are unlikely to get pregnant this week unless your cycle is irregular and ovulation occurs in the first week itself.

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shreeja pillai

Postgraduate in Chemistry and content writer. She has worked as a research analyst with a leading multinational pharmaceutical company and also holds a diploma in pharmaceutical regulatory affairs. Her interest in the field of medical research has developed her passion for writing research-based articles. She is a writer for MomJunction and aims at providing informative articles based on health and wellness. Apart from writing, she takes a great interest in music and traveling. know more about her at
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