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Getting Pregnant: How long after sex does implantation happen?

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Are you wondering how long after sex does implantation happen? Here’s everything hopeful new moms should know, plus important first pregnancy tips!

When it comes to pregnancy, timing is everything!

And, if you’re a first time mom looking to become pregnant right away, you’ll need to be as intentional and precise as possible.

However, most prospective moms don’t know what it actually takes to become pregnant outside of the basics. And that’s especially true for the more technical aspects of getting pregnant like your fertility window, implantation, and when to test for pregnancy.

Thankfully, this post covers everything you need to know about fertilization, implantation (including how long after sex implantation happens), plus other tips that are helpful for getting pregnant.

With a complete knowledge of the pregnancy process, you’ll have a much better chance of conception.

And once you’ve learned all the details of implantation, you’ll know the perfect time to take that exciting and nerve-wracking test!

How long after sex does implantation happen?

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What is implantation?

First, it’s important to have an understanding of what implantation is. Here’s a simple explanation starting with the egg and sperm:

After intercourse, sperm cells compete to be the first to fertilize an available egg. Once fertilized, the egg travels down the fallopian tube and attaches itself to the lining of the uterus.

The implantation process starts when a fertilized egg attaches to the uterine lining and burrows into the uterine wall.

If implantation is successful, the pregnancy hormone, hCG (Human chorionic gonadotropin) is released, and the embryo starts to grow. (This is the hormone that turns a pregnancy test positive).

The Implantation Timeline

Any unprotected sex you have within about 5 days of ovulation can provide enough sperm for fertilization. This means fertilization can be almost immediate or up to a few days, depending on the timing of intercourse and ovulation.

Once fertilized, it takes about 5-10 days for implantation to occur.

So, the short answer to how long after sex implantation happens is anywhere from 5 – 15 days.

Tips for Successful Implantation

Woman holds basal thermometer and app to record a rise in BBT after ovulation.

After sexual intercourse, sperm can survive for up to 5 days, but an egg is only viable for about 24 hours. So, you don’t have to have sex the same day you ovulate in order to become pregnant, but there’s still a relatively tight timeline.

Because of that, it’s important to understand your cycle and when your fertile window starts.

You can determine your fertile window by using a basal body temperature thermometer and charting. Or, you can use an ovulation predictor kit or Ava bracelet.

Predictor kits are the most accurate in determining the start of ovulation by measuring hormones in your urine. These hormones indicate unique phases of the menstrual cycle and changes in cervical mucus.

Fertility is highest the 2 days prior to and on the day of ovulation so experts recommend intercourse every other day starting 2-4 days prior to the anticipated day of ovulation.

Healthy women under the age of 40 have about a 20% chance of becoming pregnant each month if they have intercourse within their fertile window (the time just before and during ovulation).

But, pregnancy isn’t all up to the woman. The male partner must also contribute healthy and plentiful sperm. So, make sure both partners are eating well and living a healthy lifestyle.

You may also consider adding foods that increase sperm count to your partner’s diet.

Some examples of sperm-friendly foods are:

  • Eggs
  • Spinach and leafy greens
  • Dark Chocolate
  • Walnuts
  • Beef
  • Pomegrante
  • Oysters

And men should avoid:

  • Fried Foods
  • Processed Meats
  • Alcohol (can lower testosterone levels and affect the health of sperm)
  • Caffeine
  • Soy and Estrogen Rich Foods
  • High Fat Dairy Products (contains estrogen which can decrease sperm production)

What are the signs of successful implantation?

If you’ve wondered how long after sex implantation happens, you’ll probably also want to know the signs of successful implantation.

A week past ovulation, you may begin to experience some 7 DPO symptoms like nausea, bleeding, and mood swings. However, pronounced pregnancy symptoms usually don’t happen until a little further down the road (see more on that, below).

And you should also keep in mind that early pregnancy symptoms are very similar to period symptoms so this could just be a visit from Aunt Flow.

Still, there are some notable signs to look for that may indicate implantation has occurred:

  • Implantation bleeding (light bleeding or spotting that’s light pink or brownish in color, lasting no more than a couple days).
  • Cramping (similar to period cramps, lasting for a very short period time).
  • Sore breasts
  • Increased BBT (that doesn’t return to normal according to your BBT charting).
  • Disrupted menstrual cycle (a missed period is a tale-tale sign of successful implantation and pregnancy).

How do you know if implantation has failed?

If implantation fails, you probably won’t even know. Most often, the un-implanted, fertilized egg and uterine lining shed, and your normal menstrual period begins.

However, in very rare cases, a fertilized egg that fails to implant can cause a spike in hCG levels, triggering a false positive pregnancy test. This is referred to as a chemical pregnancy.

Failed implantation may also cause a heavier than normal period which can be accompanied by more menstrual cramping than usual.

When should you see a doctor?

It’s a good idea to meet with your doctor just before you plan to become pregnant. They can provide you with helpful information about your unique body and give guidance on any medications you may need to start or stop taking as well as helpful supplements.

If you haven’t had pregnancy success after about 12 months, you should meet with your doctor again or a fertility specialist to ensure there are no underlying issues.

How long after sex can you take a test?

A couple wearing white shirts embraces as they look at the results of a pregnancy test.

Now that we’ve established how long after sex implantation happens, it’s also important to know how soon after implantation you can test for pregnancy.

For the most accurate results, you should wait until after your first missed period. Though, it’s possible to receive a positive pregnancy test as early as 1-2 weeks after intercourse.

If you decide to check early, and the test is negative, be sure to check again after a little more time has passed. It takes a while for hCG to build up enough in the body to be reliably detected.

Early Pregnancy Symptoms

Contrary to popular belief, pregnancy is calculated from the date of your last period, not after sex or when implantation happens. And most women won’t feel any pronounced or extreme pregnancy symptoms until 4 weeks from their last menstrual cycle.

Pregnancy symptoms vary from woman to woman and can even vary from pregnancy to pregnancy.

But, here are some of the most common early pregnancy symptoms you may experience:

  • Morning sickness
  • Nausea
  • Bloating
  • Cramping
  • Fatigue
  • Headaches or more frequent headaches
  • Frequent urination
  • Increased blood pressure

Later on in pregnancy (7-12 weeks), you may begin to experience:

  • Heartburn
  • Nipple changes
  • Changes in the skin (more/less breakouts)
  • Changes to hair and nails
  • Back pain
  • Noticeable weight gain

NOTE: If you notice heavy spotting or bleeding, extreme abdominal pain, intense lightheadedness, or abnormal or smelly discharge, talk to your doctor right away as these can be signs of a miscarriage or ectopic pregnancy.

The Bottom Line

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How long after sex does implantation happen? Here’s the bottom line:

  • If a healthy woman under 40 has intercourse during her fertile window, she has a 20% chance of becoming pregnant.
  • The fertile window occurs a few days before and during ovulation.
  • Sperm released into the vagina within 5 days of ovulation can fertilize an egg.
  • After fertilization, the implantation process takes between 5 and 10 days.
  • After sex, implantation can occur anywhere between 5-15 days.

If you’ve followed the best practices for successful fertilization and implantation and aren’t able to conceive after about 12 months, reach out to your doctor or a fertility specialist. They can help determine whether there are underlying issues preventing pregnancy.

But don’t get too discouraged, it’s typically just a matter of timing!


How long after sex does implantation bleeding occur?

Conception, or the successful joining of the sperm and the egg, can happen as soon as minutes after sex or up to 5 days. After that, implantation (and subsequent implantation bleeding) happens anywhere from 5 – 15 days after sex.

Implantation blood will typically be a light pink or brown color and might be accompanied by mild cramps.

Want More?

If this post for understanding implantation after sex was helpful, be sure to check out:

Your Turn

If you need more info on how long after sex implantation happens or other pregnancy questions, let me know in the comments!

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