A: Women's menstrual cycles vary from month to month and from woman to woman. A typical cycle, from the beginning of one period to the next, is 26 to 32 days. Ovulation occurs approximately two weeks before the beginning of a period. With a 26-day cycle, then, your fertility peaks on the 12th day (26-14=12). Similarly, you would ovulate on day 18 in a 32-day cycle.

Once pregnancy occurs, a light flow or spotting may occur when the period is expected. Although it is commonly mistaken for a cycle, it's not. It is probably related to the implantation of the pregnancy in the uterus.

Although I have heard of women saying they still have monthly periods while pregnant, I have not seen it in any of my patients nor read about it in any medical articles.