Pregnancy is a basic yet complicated process! Many people (not just youth) aren’t sure exactly the steps involved in how exactly pregnancy occurs.
The simple explanation is that the sperm and the egg cells join and develop in the uterus for approx. 9 months until the fetus is ready to be born.
However, in order for sperm and egg to meet, sperm need to be produced in and released from the testicles, an ovum (or egg cell) must be released from the ovaries and the two need to be joined together in a step called fertilization. This can happen inside the fallopian tubes or with the help of a reproductive health specialist in a laboratory.

After fertilization occurs in the fallopian tubes, it usually takes several days for the fertilized ovum to make its way to the uterus (it could also be placed there by a reproductive health specialist) and implant into the lining of the uterus called the endometrium. Once it implants into the lining and begins to develop, pregnancy has begun. The egg is now referred to as an embryo and as it develops later it is called a fetus.

The Three Steps of Pregnancy


1. Ovulation: The ovary releases an egg

During the monthly cycle, hormones cause the eggs or ova cells inside the ovaries to mature. About every 28 days or so, one egg is well developed enough to be released from the ovary. This is called ovulation. Immediately after the egg is released, it travels down the fallopian tube where it stays for about 24 hours. The egg is only able to be fertilized by a sperm cell for about the first 24 hours. If the egg is not fertilized during that time, the egg breaks down. Your period will begin approximately 2 weeks later.

2. Fertilization: Sperm meets egg

The mature egg is fertilized when it is joined with a sperm cell. This usually happens after a penis has ejaculated semen inside a vagina. Sperm is contained in the semen which travels up the vagina, through the cervix and uterus and into the fallopian tubes. If an egg is less than 24 hours old, it can be fertilized by a sperm. This usually happens in the fallopian tubes.

Fertilization sometimes (but rarely) happens when semen has been ejaculated outside but near the entrance of the vagina. Technology can also be used to fertilize an egg, either by inserting semen into the female’s body (artificial insemination) or by fertilizing an egg outside the body and then placing it into the uterus.

3. Implantation: The fertilized egg attaches to the lining of the uterus and pregnancy begins.

Most eggs are fertilized by sperm while still in the fallopian tube. The fertilized egg then travels down the fallopian tube into the uterus. This can take a few days. When the egg reaches the uterus, it may attach itself to the uterine lining (the endometrium) and pregnancy will begin. Some fertilized eggs are never implanted and as a result, they break down and leave the body with the next period.

Does ovulation always happen at the same time every month?

Ovulation is different for everyone and it can change from cycle to cycle–especially when you are a teenager and your body is still developing.
Changes in vaginal fluids, slight cramping, and increased sex drive can all be signs of ovulation


Useful tip

Even though an egg can only be fertilized within 24 hours of being released, sperm can live inside the body for up to five days. That means that you can have sex when you’re not ovulating and still become pregnant if the sperm is still present in the uterus when you do ovulate. In other words, sperm that was ejaculated on Monday could fertilize an egg released on Thursday.