Yes, I believe this is true. I think it's usually due to the fact that a lot of CFers are malnourished/underweight, which tends to alter a woman's periods. For me, I started quite late (I think I was 16 yrs old) and was quite skinny at that age. Even when I did get my periods, they were very irregular and I usually only got 6-8 per year. As I got older and I gained weight, they became more regular.
