A pregnancy test detects the presence of the pregnancy hormone human chorionic gonadotropin, or hCG, in a person’s body. But the body doesn’t produce that hormone until several days after conception.

A pregnancy test detects the presence of the pregnancy hormone human chorionic gonadotropin, or hCG, in a person’s body. But the body doesn’t produce that hormone until several days after conception.

WASHINGTON — Earlier this year, Rep. Michelle Steel, a two-term Republican in a competitive district in Orange County, California, co-sponsored the Life a t Conception Act with 124 other GOP backers, ...