Fertilization is considered complete when this event occurs. see section 21.1 ( page 482)

The process of implantation starts by the 7th day with the trophoblast contacting the uterine wall. This induces the trophoblast to secrete enzyme that erodes the uterine wall only at the point of contact. This point would be made use of by the trophoblast and by the 14th day the blastocyst would be completely burrowed and implanted within the uterine mucosa.During the 14th day of the normal menstrual cycle, the secondary oocyte under the influence of luteinizing hormone and estrogen undergoes ovulation.

Each names a given number of objects