I started my menstruel cycle with light spotting of dark/blackish blood. That lasted approx 1 week. Then flow turned abnormally heavy with a lot of large clots. I am using more pads in a day than i normally do in a week. I have hypothyroidism and was on a 150 mg dose for several years. Recently upped to 200 for 3 months. Reduced to 175 for about 1 1/2 months now. I also have a hiatal hernia. I am terrified because start date of this cycle was 12/23. It lightened for a day or two and is back with a vengeance. I am feeling weak, lightheaded and lethargic, i assume from loss of blood. I am afraid of what a doctor may find as cancer, nearly any/every variety including ovarian & breast runs in family. My breasts are also extremely sore/sensitive and i have been using quite a bit of sinus products containing pseudoephedrine. I am also 48 years of age so could be start of menopause? My periods until now have been fairly normal and last 3-5 days, rarely heavy. Your opinion if any?