Hi Chiswick,
Welcome!
I too would ask specifically why your Dr feels it is "worrisome".
I have had very short cycles for years - about 3 weeks in between, and have had several Dr's tell me the only real concern would be that I might become Anemic. So far I have not - but make sure to take iron, folic acid and vitamin c (which helps utilize the iron) and eat my spinach. : )
You definitely should read up here - there is a ton of helpful info and stories....and here is a link to where you can see some of the more common signs of peri-menopause. Peri is the term used when you have begun to exibit the signs that your body is starting to change - but you still have periods. So many of us that visit Power Surge are right where you are.
Click here for a quick outline -
http://www.power-surge.com/educate/menoprimer.htm
As for Ovarian failure - I don't know exactly what that means or what should be done about it, but I would ask your Doctor. Remember that your Dr. works for YOU, and it is YOUR body. I agree with Little Troll - and also feel that if your Dr is showing concern, then she needs to tell you why - as in, exactly what she is concerned about, and what your treatment options are. Simply telling you it is "worrisome" is not only NOT helpful, I think it is unprofessional. Her job is to help you understand what is going on so that you can decide what you want to or need to do.
Women can go into peri-menopause as early as 30 - but most start around 40-45. 45 is definitely in the ball park of a reasonable age to start seeing changes in your cycle. I would be a little upset, too. You may want to consider changing Dr's if you are not comfortable with her or she is not being helpful.
Peace,
-Mary Beth