The Female Body:
To understand conception, it is helpful to know about female reproductive system and the menstruation cycle. A female is born with about 400,000 eggs in their ovaries. The female obody begins to ovulate during puberty. About once a month, several eggs mature, and the lining of the uterus has been building and has become thick to act as a “nest” for the egg to implant. Then an egg is released from the ovary. If it is not fertilized within 12-48 hours, it disintegrates. Approximately 2 weeks later, the thick lining of the uterus is shed, and you begin menstruating. Your next menstruation cycle then begins again.
When Do You Ovulate:
Ovulation is the release of the matured egg from the ovary. In response to a hormonal signal, the follicle (holding the egg) bursts open and frees the egg - this is when you ovulate. Ovulation typically occurs around 14 or 15 days from the first day of the female's last menstruation cycle. Once you ovulate, the ovum (egg) travels into the fallopian tube and is receptive to fertilization by a sperm.
When Do You Ovulate?
"The Fertile Period":
Once you ovulate, this is the most fertile period for the female body. This is the time when conception can occcur, and you are most likely to become pregnant. Since the egg has been released (i.e., you ovulated) and is available for fertilization, if a female engages in unprotected intercourse, fertilization and conception can occur. A female is most fertile during ovulation and can become pregnant from unprotected sexual relations that took place anytime during this fertile period - basically, from the 5 days before ovulation to 1 days afterwards.
Are There Certain Times To Be More Careful?
Conception occurs after the female’s egg is fertilized by a male’s sperm. After sperm are ejaculated in the vagina, they swim through the cervix and into the Fallopian tubes, where fertilization and conception usually takes place. Once a single sperm has penetrated the egg, conception has happened as the genetic material from the sperm and the egg has merged into a single nucleus (called a "zygote").
Medical experts (e.g., the FDA and the American Medical Association) agree that the establishment of a pregnancy takes several days and is not completed until a fertilized egg has implanted in the lining of the woman's uterus. A woman is considered to be pregnant once the implantation of the zygote has occurred.