The vast majority of the medical community agrees that life begins at conception.
In one study, 96% of medical experts and embryologists agree that human development begins at conception (or fertilization). This was as study that included 5,577 of these professionals. The majority of these biologists identified as liberal, pro-choice, non-religious, and Democrat.[1]
[1] Pro-Life Cheat Sheet, PROLIFE_MILLENNIEL
Standing Before God, This We Are and No More 