How does a Woman get Pregnant?
For a woman to get pregnant, a male sperm must fertilize the egg that her ovary releases about once a month.
A woman’s egg stays alive for just 12 to 24 hours after release. Therefore, to be able to fertilize the egg, sperm must be present in the fallopian tubes during that window of time.
Sperm can survive inside a woman’s fallopian tubes for up to a week. That means that for an egg to get fertilized, sperm must arrive in the tubes no earlier than a week before ovulation.
Therefore, sperm have a chance to reach the tubes and fertilize the egg between one week before ovulation and one day after ovulation.
Sperm is found primarily in a man’s semen (cum), but small amounts are also in pre-ejaculatory fluid (pre-cum).
In order for sperm to reach the fallopian tubes, a certain amount of either type of sexual fluid must enter the vagina (the only opening of the female body that leads to the fallopian tubes).
This, excluding artificial insemination, can only happen through unprotected sexual activities.
In sum, in order to get pregnant, a woman needs to engage in unprotected sexual activities that allow semen (cum) or pre-ejaculatory fluid (pre-cum) to enter her vagina during a time period that begins one week before ovulation and ends one day after ovulation.