Pregnancy should always be considered in a sexually active woman who misses her period. A urine pregnancy test is easy to do and available in most drugstores. However, there are other possibilities a missed period could signal that are important to understand.
First, missed or irregular menstrual cycles may be related to a woman’s method of birth control. A menstrual cycle occurs when a woman ovulates but does not get pregnant that month. The lining inside the uterus that was built up to support a pregnancy is then shed off when no pregnancy occurs. Oral contraceptives (birth control pills) suppress ovulation and can cause missed or irregular cycles because they are low dose (20-35 micrograms of estrogen per pill per day) and may not build up much lining. If the lining in the uterus is thin, there is not much to shed off during her period, so it may only look like spotting or no bleeding at all. The blood is not left inside -- it was never produced.
But if the birth control pills are taken correctly -- every day approximately the same time, don’t double them if you forget one -- then pregnancy should not result. There is a 1% failure rate if used correctly. Spotting does not mean they are not working to prevent a pregnancy, it just means they aren’t holding up the lining very well. If the birth control pills are not taken properly, spotting may occur and there is a risk of pregnancy with only one or two missed pills per cycle.
Missed or irregular periods can also be the symptoms of several gynecological conditions. Let’s review two of them.
Polycystic Ovaries (PCO) occurs in approximately 5% of women. Missed or irregular menstrual cycles are the first clue. Other symptoms may be overweight/obesity, acne and hirsuitism (a lot of hair-body, facial or both).
Blood tests and a pelvic sonogram can confirm the diagnosis. Some women have no symptoms other than missed or irregular periods. A normal menstrual cycle represents normal hormone levels of estrogen and progesterone-necessary for a woman’s body.