How does it work?
When you reach puberty, your ovaries start producing oestrogen and progesterone. These hormones make your womb get thicker once a month and ready for getting pregnant.
Meanwhile, their are hormones also signalling your ovaries to produce, and release an unfertilised egg. In most women, this happens once every 28 days or so.
No fertilisation = getting your period
In general, if you don't have sexual intercourse around the time of your ovulation (when your ovaries release an egg), it's unlikely that any sperm reaches and fertilises your egg. So what' happens is your uterus lining that has recently thickened, will be shed as menstrual blood. And you get your period! This cycle is called menstruation.
If you’ve only just started having periods, you might not actually ovulate yet. This is a natural way to protect you if your body is not actually ready for pregnancy just yet.
During the first year you have your periods, you may only ovulate (release an egg) 20 percent of the time. This means that if you have 12 periods a year, during only two for every 12 periods, 10 or 11 times an unfertilised egg will come out.
Remember, every woman is different and once you’re sexually mature you can get pregnant any month! You can even get pregnant if you’ve never had a period. Don’t think just because you’ve not been having periods for long you don’t need to use contraceptives. That could be a very big mistake!
You’re only able to have a baby during certain times of your life. For many women, this is between about the ages of 15 and 49, where you have your monthly periods and are ovulating regularly.
Most young women tend to ovulate every month, in between their periods. During ovulation, an unfertilised egg cell travels out of the one of the ovaries and down the fallopian tube to the womb.
To get pregnant, you have intercourse with a man around the time you ovulate – from about five days before until one day after. After sex, the sperm swims up the vagina to the fallopian tubes. If there’s an egg waiting in one of the fallopian tubes, the tiny sperm try to burrow their way inside it. If one sperm gets inside the egg, it’s fertilised.
The fertilised egg then moves down the fallopian tube to the womb. Hormones make sure the lining of the womb is ready to receive the egg. If the fertilised egg nestles into the lining of womb, you’re pregnant.
Fertilisation and ovulation
When you ovulate, if there are no sperm cells in your fallopian tube – either because you haven’t had sex or you used a contraceptive – then the egg won’t be fertilised. Your body then gets rid of the lining of the womb, so mucous and blood comes out of your vagina. This is called menstruation, or having your period. In general, it lasts between 4 and 7 days.
Your menstrual cycle runs from the first day of your period to the first day of your next period. This takes about 28 days (4 weeks), but different people’s cycles vary between 21 – 42 days (3-6 weeks).
Phase I: Menstruation (Day 1 to Day 5)
On the first day of your cycle, the tissue from the lining of the womb, the blood, and the unfertilised egg cell leave your body through your vagina. You’ve now got your period. In a 28-day cycle, this phase lasts between one and five days. Don’t worry if your period is as short as 2 days or as long as 8 days. This is normal.
Phase II: Follicular (Day 6-14)
After your period ends, your womb lining begins to get thicker. Also one of your ovaries produces one mature unfertilised egg. You may notice changes in vaginal discharge. It may become stickier, white, milky, or cloudy. These changes may signal that you are entering the fertile time of the month.
Just before you ovulate, your vaginal discharge may change to a texture and colour similar to a raw egg white. This discharge can be slippery and clear, which can help sperm travel to the egg. Like the menstruation phase, this phase can be as short as 7 days or as long as 19 days.
Phase III: Ovulation (Day 14)
During ovulation, the ovary releases a mature egg, which passes into the fallopian tube. Some young women may feel a slight pain on one side of their lower back or abdominal area around the time of ovulation. This too is normal. Ovulation takes place about 14 days after the first day of your period. Meanwhile the lining of your womb gets even thicker.
Signs of Ovulation
Some young women experience changes when they are ovulating like:
- a change in vaginal discharge
- a brief pain or dull ache felt on one side of the abdomen
- an increased desire for sex
- a bloated abdomen
- a keener sense of vision, smell, or taste
Phase IV: Ovulation to Menstruation (Day 15-Day 28)
The released egg travels down the fallopian tube to the womb. The womb lining gets even thicker to receive the egg. If the egg isn’t fertilised by a sperm cell, it dies. Your body gets rid of the extra womb lining and egg cell, and your period starts again.
If the egg cell is fertilised and it settles into the lining of the womb, and your period doesn’t come: you’re pregnant. The menstrual cycle stops until after you give birth.