1. Don,t be in the illusion that the stork come only during monthly cycle. There have been many cases of oblivious women falls pregnant as they think it their period. Your actual menstrual cycle work as a strong contraception, a lot of women also bleed or have mild cramp in the abdomen at the time of ovulation (when an egg is released from your ovary every month, that egg has a chance of getting fertilized). This is the time to boost your chances of getting pregnant or of preventing pregnancy if that& what you are trying to do. Another development, which is more common than you think is that sometime you ovulate even before your period gets over or just after a couple of days after you stop bleeding. Experts says that since sperm are tenacious and can stay in your body for two to three days even after intercourse, having sex during your this period (without any use of contraceptive or protection) can result in pregnancy. 2. On an average woman’s monthly cycle can be anything between 24-45 days depending on her genes, hormones, environmental factors, physical and mental well being. It common to have your cycle go through changes due to hormonal change. As women get older, their cycles usually tend to get shorter. This is also when your body starts entering perimenopause (the period of a woman's life shortly before the occurrence of the menopause). If Perimenopause symptoms really bother you, dont hesitate to visit your gynecologist.