IN HUMANS -
Since ovulation usually occurs around 14 days after the first day of your period, fertilization usually takes place in “week 3” of pregnancy. So, for the first two weeks of the gestational period, you're not actually pregnant at all.
IN PLANTS -
Fertilization takes part in the ovary of a female flower. Wind or pollinators carry the pollen from the male anthers to the female flower parts. After the pollen lands on the stigma, a pollen tube forms, and male reproductive material travels down the style and into the ovary, where it fertilizes an ovule.
