Each monthly menstrual cycle begins with menstruation. Most women find the time from the beginning of one menstrual cycle to the next to be fairly predictable and consistent. Some women, however, find their next menstrual cycle delayed when menstruation does not begin as expected. Although the cause of this could be harmless, it also may be a sign of a serious problem. Women who miss a menstrual period should talk to a doctor to determine the cause.
Late Ovulation
Although ovulation usually occurs half-way through the menstrual cycle, there are times when ovulation occurs much later than usual. Stress, extreme dieting or exercise, illness and certain medications may cause late ovulation. The time from ovulation to menstruation is typically consistent and lasts approximately 14 days, explains the Merck Manuals. Therefore, the later a woman ovulates in the month, the later she will receive her period and the later her next menstrual cycle will start.
Medical Conditions
Medical conditions may cause hormonal imbalances that prevent ovulation from occurring at all. These medical conditions include polycystic ovarian syndrome, thyroid disease, pituitary disease, a pituitary tumor, sexually transmitted diseases, infections and menopause. Women who believe they may have one of these conditions should contact their doctor for advice. Breast-feeding women often experience hormonal changes that delay or suppress menstruation as well, but their cycles should become regular once nursing stops. In addition, congenital abnormalities or previous surgeries done on the pelvis or abdomen may also prevent menstruation from occurring, explains PRD Health.
Birth Control
Hormonal birth control can also cause menstruation to occur later than usual or not at all. Women who take birth control pills or use the patch or vaginal ring typically bleed when they stop taking the medication. If they fail to remove the patch or ring on time or skip the inactive birth control pills and continue taking the active pills, the hormones from the medication remain in the body and prevent this bleeding from occurring. In addition, birth control shots and intrauterine devices also may cause irregular or absent periods, explains the American Pregnancy Association.
Pregnancy
Women who are sexually active and have a late period may be pregnant. Most home pregnancy tests are accurate as soon as a woman misses her period, and this can be a convenient way of finding out if this is the cause of the missed period at home. If the results of a home pregnancy test are negative or unclear, a blood pregnancy test done in a doctor office can confirm if pregnancy is the reason for the late menstrual period.
