As you may know, you cannot get pregnant every day of your cycle. The fertile window is the optimal time during the female cycle to have intercourse. Typically the fertile window comes 10-14 days after the start of menstruation in a 28-day cycle.
The fertile window is around 6 days long, and it is the only period in a month when a woman can get pregnant. This includes the day of ovulation and the rate of sperm survival, as sperm can live in the female reproductive system for up to five days before an egg cell is even released! Getting pregnant during your menstrual cycle is unlikely, though not impossible. Because cycle lengths vary from woman to woman, a general rule is that ovulation typically happens 14 days prior to the start of your next menstrual cycle.
Unlike sperm, the egg cell starts to deteriorate quite quickly after ovulation happens and is only able to be fertilized for 24-48 hours. For this reason and to increase the chances of conceiving, it’s best to have sex the day before ovulation happens.
So, a fertile window is the most important time during the month if you want to conceive. Sex outside of this window tends not to lead to pregnancy.