Does it make a difference when it's YOU?
A partial list of embryology textbooks that state the biological fact that human life begins at conception:
Essentials of Human Embryology, 1998, pgs 1 & 14
Human Embryology and Teratology, 3rd edition, 2001, pg 8
The Developing Human: Clinically Oriented Embryology, 7th edition, 2003, pgs 2 & 16
Langman's Medical Embryology, 10th edition, 2006, pg 11
Before We are Born: Essentials of Embryology, 7th edition, 2008, pg 2
If you want older texts, here are some more:
Patten's Human Embryology, 1976, pg 30
Biological Principles and the Modern Practice of Obstetrics, 1974, pgs 17 & 23
Pathology of the Fetus and the Infant, 1975, pg vii
A statement of the American Medical Association from 1857 (cited by Wade in Roe v. Wade): "The independent and actual existence of the child before birth, as a living being, is a matter of objective science. It is a popular ignorance that the fetus is not alive until after the period of quickening."
Also, in 1981, a US Senate judiciary subcommittee heard testimony from multiple sources and reached this final conclusion: ""Physicians, biologists, and other scientists agree that conception marks the beginning of the life of a human being - a being that is alive and is a member of the human species. There is overwhelming agreement on this point in countless medical, biological, and scientific writings." (Subcommittee on Separation of Powers to Senate Judiciary Committee S-158, Report, 97th Congress, 1st Session, 1981)