The initial signs of pregnancy can provoke feelings from joy to dread, depending on the woman’s desire to be pregnant, her partner’s feelings, and a variety of surrounding

circumstances. Although some women have either a light blood flow or spotting (irreg­ular bleeding) after conception, usually the first indication of pregnancy is the absence of the menstrual period at the expected time. Breast tenderness, nausea, vomiting, or other nonspecific symptoms (such as extreme fatigue or change in appetite) can also accompany pregnancy in the first weeks or months.

Any of these clues might cause a woman to suspect that she is pregnant. Medical techniques such as blood or urine tests and pelvic exams can make the determination with greater certainty. The blood and urine of a pregnant woman contain the hormone human chorionic gonadotropin (cohr-ee-AH-nik goh-na-duh-TROH-pun) (HCG), which is secreted by the placenta. Sensitive blood tests for HCG have been developed that can detect pregnancy as early as 7 days after conception. Commercially available at-home pregnancy urine or saliva tests can detect pregnancy shortly after a missed menstrual period. Because elective home pregnancy tests can yield both false-positive and false-negative results, a health-care practitioner should confirm the results.