Irregular menstrual periods can make pregnancy planning more difficult. But do not be discouraged yet, this does not mean you can not get pregnant. With patience, there are always ways you can get baby. Menstrual periods are called irregular if they last less than 21 days or longer than 35 days, also if the length of the menstrual period is significantly different from month to month. Irregular menstruation can unfortunately also affect the chances of pregnancy. Things You Need to Do to Plan a Pregnancy There are various causes of irregular menstrual periods, from obesity, perimenopause (the period leading to menopause), thyroid disorders, stress, to polycystic ovarian syndrome (PCOS). To determine the cause, you need to see a doctor. In addition to finding out the cause of irregular menstrual periods, you need to know also how irregular your menstrual period is and make arrangements for sexual intercourse when planning a pregnancy. Although it is more difficult, you can still ...