When does conception occur?

How does conception occur?

In very basic terms, conception happens when a male sperm cell meets and fertilizes a female egg cell. This fertilized egg then becomes an embryo, and this is the start of pregnancy! 

In reality, though, getting pregnant is a bit more complicated than that. We’ve broken down the steps so you can better understand the conception timeline:

1. Ovulation

For conception to happen, you need a female egg cell. An egg cell is typically released during ovulation (but it can also be retrieved by IVF). In a typical cycle, the egg cell is released from the ovary around the middle of the cycle. Once released, it travels down the fallopian tubes. An egg cell can only live for a maximum of 24 hours, which is why timing is so important!

2. Sperm makes its journey

When a male ejaculates during unprotected sex, sperm cells are released into the female’s vagina. They then make their way toward the fallopian tubes, traveling through the cervix and into the uterus. Sperm can live in the female reproductive system for up to five days, so in theory, they can be there days before the egg cell is released and conception can still happen!

3. Fertilization

This can depend on when you time sexual intercourse, but the sperm usually meets the egg in the fallopian tube. There might be lots of sperm, but only one will successfully penetrate the egg’s protective layer to fertilize the egg. This process is called fertilization or conception.

4. Formation of the zygote

When the sperm and egg fuse together, the new cell that’s formed is called a zygote, this contains the genetic information that’s needed for development. This zygote travels from the fallopian tubes to the uterus, roughly three to five days after fertilization.

5. Implantation

After fertilization, the zygote begins to divide and forms something called a blastocyst, which is a cluster of cells made from the fertilized egg. Eventually, the blastocyst turns into the structures that protect the embryo. The blastocyst stays in the uterus for a few days before it attaches to the inner lining of the uterine wall, in a process called implantation.

6. Pregnancy

It’s only after implantation, around the time when your next period is due that you are likely to get a positive pregnancy test. At this point, the fertilized egg continues to grow and develop, receiving nourishment from the mother’s body through the placenta. Over time, it develops into an embryo, then a fetus, and eventually, a baby. 

How long does conception take?

Conception can happen as soon as 30 minutes after ejaculation during sexual intercourse, or it can take several days. It’s all about timing.

An egg can be fertilized between 12 and 24 hours after it’s released into the fallopian tubes. After that time, the egg cell starts to deteriorate and after 24 hours it can no longer be fertilized.

However, sperm survival rates are high, and they can survive in the female reproductive tract for up to five days, awaiting an egg to fertilize. Depending on where you are in your menstrual cycle, then, conception could potentially happen a few days after sexual intercourse. For example, if you have unprotected sex, and then ovulate three days later, you could potentially get pregnant. 

While they live longer than egg cells, sperm cells do die off over time too so if you are trying to get pregnant it’s best not to time sex too far in advance of ovulation. Having intercourse the day before ovulation may increase your chances of conceiving - but to do this, you need to know when you ovulate. (More on that later!)

Does pregnancy start on the day of conception?

Pregnancy doesn’t start on the day of conception. It's not one moment but is a process, and there are a number of biological steps that need to happen before pregnancy can be confirmed.

Conception usually happens between 11 and 21 days after your last period, of course, all our cycles are different so this can vary from person to person. This means it’s hard to determine the exact date of conception – however, most of us know roughly when our last period was. If you’re pregnant, this is how healthcare professionals will calculate your due date: by counting 40 weeks from the date of your last menstrual period.

Does conception always lead to pregnancy?

Even when you time sex right, it doesn’t always lead to pregnancy. There are various reasons for this, but they can include:

• Low sperm count
• Issues with sperm mobility
• Anovulation (when you’re not ovulating)
• Implantation failure (the fertilized egg doesn't attach to the uterine lining)
• Decreasing sperm quality
• Decreasing amount of quality eggs
• The overall health of both partners
• Pelvic infections (previous or current)

There are lots of different factors at play when it comes to how long it takes to get pregnant. If you’re concerned, speak to your doctor or OB-GYN to get more info.

How does conception work in IVF?

Everyone’s fertility journey is different, and for some people, conception may happen through in vitro fertilization (IVF). This process happens outside the body with the help of medical professionals. The egg cell is extracted from the fallopian tube and is mixed with sperm (both the egg and sperm can either be from the parents to be or from donors).

Usually, the sperm will break through the egg’s protective barrier on its own, but sometimes it will be injected directly into the egg cell.

After this process takes place, the fertilized embryo may be grown for a little longer in the lab before being placed in the uterus, where it will hopefully implant, resulting in a pregnancy. 

How to know if conception has happened

You more than likely won’t know that conception has taken place, as there aren’t usually any signs or symptoms - although some women experience spotting when the fertilized egg cell implants into the uterine wall - this is known as implantation bleeding. 

Early pregnancy symptoms usually start when human chorionic gonadotropin (hCG) is released. This is a hormone that’s produced by the placenta during pregnancy, helping to thicken the uterine lining to support a growing embryo. It also signals to the body to stop menstruation. 

HCG levels start to rise after conception and continue to rise for around the first 10 weeks of pregnancy. Increased hCG levels rise very quickly in early pregnancy, doubling every two to three days for the first few weeks, and can be detected in the body as early as 11 days after conception. It’s these pregnancy hormones that pregnancy tests are designed to test for.

Some early pregnancy symptoms include:

• Feeling nauseous
• Feeling tired
• Mood changes
• Missing a period
• Light bleeding or spotting
• Sensitive breasts or breasts that feel fuller
• Darkening of the areola (the area around the nipples)

Keep in mind that a lot of these symptoms are similar to those of premenstrual symptoms, (PMS), so it can be hard to know if you’re pregnant or expecting your period - if you’re in any doubt, it’s a good idea to take a pregnancy test.

If you have a regular menstrual cycle, it’s usually recommended to wait until the day after your missed period to take a pregnancy test, although some tests are more sensitive to hCG levels and can detect lower levels of the hormone, meaning they can detect pregnancy earlier. So always make sure to read the instructions on the specific test you’re using!

The importance of timing

If you’re planning a pregnancy, timing is important. You can’t get pregnant on every day of your menstrual cycle – in fact, there are only a few days every month when it’s possible, known as the fertile window. This includes the day of ovulation, and the five days before it.

Knowing when you’re fertile gives you a better chance of conceiving, as you can plan to have sex on your most fertile days. Typically, the best time to have sex if you want to get pregnant is one or two days before ovulation, as this gives the sperm time to reach the egg cell before it starts to deteriorate.

You can predict ovulation and plan the best time to get pregnant during the fertile window using Natural Cycles. The Natural Cycles app is powered by an algorithm that analyzes basal body temperature data, along with other factors, to predict and identify ovulation. That means you can better plan for conception based on your unique menstrual cycle. Research has shown that Natural Cycles users get pregnant in three cycles on average. 

You can also use Natural Cycles as hormone-free birth control before or after pregnancy. Ready to plan your pregnancy, why not see if Natural Cycles is the right option for you today?