the product of conception. That is all the structures derived from the zygote and includes not only the embryo, but also the placental and membrane components formed from the conceptus. (More? Week 1 Notes)
Conceptus (latin is conceptio, derivatives of zygote) denotes the embryo and its adnexa (appendages or adjunct parts) or associated membranes (i.e. the products of conception) The conceptus includes all structures that develop from the zygote, both embryonic and extraembryonic. It includes the embryo as well as the embryonic part of the placenta and its associated membranes - amnion, chorionic (gestational sac), and yolk sac.