What Are the Earliest Signs of Pregnancy Before a Missed Period?

While most proven methods of contraception, such as condoms or birth control pills, are 94 to 99 percent effective when used as directed, human error in their use, defective products or sheer bad luck can lead to contraceptive failures and unexpected pregnancy. A missed period is actually one of the earliest signs of a pregnancy, since ovulation takes place about two weeks before the menstrual period begins, fertilization, if it's going to happen, usually takes place within about a day of ovulation and the fertilized egg can take six to 12 days to implant and let your body know you're pregnant. There are, however, some other early symptoms that indicate you might be pregnant.

Within Days

The first symptom many women notice of their pregnancy is implantation bleeding, which can happen within a week or less of your expected menstrual period and may be mistaken for spotting, an irregular menstrual period or abrasion from the act of intercourse. Alternatively, this sign of pregnancy may be legitimately explained by any of the other conditions. Implantation bleeding is usually lighter in color and volume than normal menstrual flow. You may also experience some abdominal cramping, either in conjunction with implantation bleeding or independently.

Within Weeks

Extreme fatigue is an early symptom of pregnancy that may kick in as little as a week after conception, or shortly before your menstrual period is due. Another symptom of pregnancy that may arise within the first two weeks---which means you might notice it just before you notice a missed menstrual period---is swollen or tender breasts. This may be mistaken for, or explained as, a symptom of PMS or the effect of birth control pills.

Nausea (sometimes known as morning sickness, though it may occur at any time during the day or even last all day), with or without vomiting, may signal a pregnancy as early as two weeks after conception, placing it close to or just after a missed menstrual period, although some women never experience pregnancy-related nausea at all.

Other

Miscellaneous symptoms that may occur during the first weeks of pregnancy---perhaps showing just before a missed period---and continue for the duration, although some women never experience them at all, include headaches and backaches. You may notice your areolas (the skin around your nipples) darkening due to pregnancy-related hormonal changes, and you may have unusual food cravings or aversions. You may also notice yourself reacting strongly to certain smells, as pregnancy tends to dramatically enhance a woman's sense of smell.