PLEASE HELP-- Change in menstrual flow-- PLEASE ADVISE!

Hi, I am 26 and for the past 6 - 12 months I have noticed a change in my menstrual flow. I have always been fairly regular with a regular flow (fairly heavy and then tapering off, for a total of 5 days), but it has begun to follow the following pattern:

I will normally have a day or so of brown/red small discharge/spotting about a few days before my period. It goes away for a couple of days or so, and then my period starts. It is usually a medium flow for a few days and tapers off very, very slowly, lasting 5-6 days. I then go back to normal. It's also become a little more irregular, occuring up to a week early some months, but this doesn't happen often.

I have had the same partner for the past 2 years. Neither of us has had an STD or cheats, and I've never had children. I'm not on the pill, I have regular cramping, and the rest of my discharge has been normal. I have been pretty stressed for the past year or so, but this menstrual change has become quite consisitent. I am on no medications, I have a healthy, balanced diet, and am quite healthy overall.

Could this just be a normal, quarter-life change? Hormonal imbalance? Or should I be concerned that this could be something more?????? I'm a bit afraid to speak up to the gyno because they always make me feel silly for asking questions.