Doctor Betti Dr. Betti Hertzberg Ressler is a Board Certified Pediatrician on staff at Miami Children's Hospital. Dr. Hertzberg developed the toilet training video "Let's Go Potty." She is the co-author of "The Doctor's Book of Home Remedies for Children." Irregular Periods Question: My daughter is 13 and her period started in May of this year. How regular will her cycle be. She seems to get it one month in 39 days and another 17 days. Is this normal? - Suzanne Answer: Dear Suzanne, Menarche (the beginning of menstrual cycles in the female) can be very irregular. It can do so for many cycles and can last years. Ovulation (usually midcycle) can be very irregular when menstruation begins. This is one of the major reasons for the irregular pattern of periods. There are other reasons which can be diagnosed by a physician specializing in the female reproductive cycle (endocrinologist or gynecologist). If menstrual cycles become excessively heavy with severe cramping, a gynecologist may be able to help regulate and control these symptoms, as well as the cycle days. As with any problem that you don't feel comfortable with, please consult your physician. It may be that reassurance is the only thing that is needed. If treatment is necessary, that too can be looked into. Good Luck! Dr. Betti Also see: Plantar's warts Are vaccines safe? Ask Dr. Betti your questions Recently asked questions This information is not intended to be a substitute for visiting your pediatrician. If you or your child has specific concerns, you should see your doctor for a diagnosis and treatment.