Hello and I hope I can help you today. The quality and amount and timing of when you bleed during your menstrual cycles can be affected by many factors... Age, weight loss or gain, stress, hormonal changes, medications, and even problems with the uterus. Without more information about your age and general health, it really may not be possible to give you an accurate diagnosis, but I may be able to make some suggestions. Brown blood is just blood that has taken time to flow out of your vagina from your uterus. The darker and thicker the blood is, the slower it is flowing. Red blood, like when you cut yourself, is seen when your bleeding is fresh. So the color of the blood really doesn t tell much about your diagnosis, but because you describe both of these recent cycles as heavy, there may be some concern. Most women do not have periods that look and feel exactly the same every time, especially if you are over 40 years old. I recommend waiting one more month to see what happens and then seeing your GYN doctor for evaluation. He or she may be able to do tests of your hormones or be able to better advise you of the possible causes with a complete medical history and physical examination. I hope I was able to answer your question as best as possible and that this information was helpful to you. Best wishes, Dr. Brown