The earliest signs of pregnancy can include nausea, breast tenderness, mood changes and spotting, according to Mayo Clinic. These signs may occur as soon as around two weeks following conception.
Pregnant women may begin experiencing nausea three weeks following conception, and the nausea, likely caused by pregnancy hormones, may occur at any time of the day, notes Mayo Clinic. While tender breasts occur due to hormonal changes that happen during pregnancy, spotting, or implantation bleeding, results from the embryonic implantation on the uterine wall, which usually occurs 10 days to two weeks after conception. Typically, the time of implantation bleeding coincides with the next expected menses date, but this bleeding is normally less severe than menses.