Pregnancy Symptoms vary between individuals, but the most common  sign is delayed menstrual period.  Breast tenderness, nausea and vomiting could follow.  Vaginal spotting at the time of period instead of a full period as experienced on the previous months is also common.  So any abnormal light period in a sexually active person who is not practicing birth control or thinks she might remotely be pregnant should be followed by a pregnancy test.  Any pelvic pain associated with abnormal bleeding and a positive pregnancy test must be immediately evaluated by a healthcare professional.