Menstrual period: start of the cycle

You can get pregnant on particular days of your cycle each month. Your cycle starts on the first day you bleed from your vagina. This is called the menstrual period

Your cycle lasts about 28 days: 

  • Some women have a shorter cycle and others a longer one. 
  • The cycle lasts between 25 and 35 days. 
  • Some women have an irregular cycle. Every month, their cycle differs in length. 
  • The length of a woman’s cycle can change during her lifetime. During puberty, the cycle is often more irregular.
Woman standing. The focus is on the internal sexual organs.
Menstrual period: start of the cycle


About 14 days before the start of your next cycle, ovulation takes place: the egg cell leaves the ovary

After the ovulation, the egg cell is transported to the uterus. About 4 to 5 days after the ovulation, the egg cell arrives in the uterus. The uterus gets ready for the implantation of the egg cell.

Ovulation: a ripe egg cell leaves the ovary.
Transportation of the ripe egg cell to the uterus

Fertilization of an egg cell

You can get pregnant if a sperm cell fertilizes the egg cell. This mostly happens through sexual intercourse with a man. If a man ejaculates, sperm cells enter your vagina. You get pregnant if:

  • One sperm cell enters the egg cell and fertilizes it, and;
  • The fertilized egg cell achieves a successful implantation in the mucous membrane of the uterus. It will start growing.

You do not have menstrual periods during your pregnancy. However, some women may lose some blood in the first months of pregnancy.

You can get pregnant on about 6 days a month: the egg cell stays alive for 1 day, the sperm cell up to 5 days. You are fertile about 5 days before ovulation and the day after ovulation took place. In the following days, up to the days before your next ovulation, you are not fertile.

A man ejaculates inside the woman's vagina. The sperm cells swim towards the ripe egg cell.
Fertilization: one sperm cell enters the egg cell and fertilizes it.
Implantation of the fertilized egg cell in the mucous membrane of the uterus

Menstrual period: not pregnant

If the egg is not fertilized, the uterus will expel the egg and the mucous membrane. You have your menstrual period: blood leaves your body through your vagina. The menstrual period lasts 3 to 7 days. A new cycle starts at that moment.

Menstrual period: the egg is not fertilized. A new cycle starts.


If you do not have a desire to have children at the moment, use contraception.

Translate this text into:

Dictionary and translations

Looking for help? Find a health professional.