Health Issues Vegan diet causing heavy menstruation?

[Vegan-mom-of-2]

I have been vegan for almost 11 years. I became vegan at the age of 29 and just celebrated my 40th birthday a couple of weeks ago. Since becoming vegan I've had 2 children. I remained vegan through both pregnancies and my babies were born healthy, weighing 8 lbs 4 oz and 8 lbs 14 oz. Both children have been vegan since birth and are now 5 and 4 years old and very healthy. Over the last decade I've had my iron and B vitamin levels checked frequently and they've always been fine. When I stopped nursing my second child two years ago my menstrual cycle resumed only it was much heavier, longer and more frequent than ever before. My iron level is now extremely low and my hemoglobin is also very low. I've had numerous tests and there is no physical reason that can explain the bleeding (ie thyroid is fine, uterus symmetrical, no fibroids). Medication (birth control pills) have failed to slow the bleeding and I now have a hysterectomy scheduled for March. Iron supplementation has been useless because, as my doctor said, "it's like trying to fill a leaky pot." I've noticed in recent months that I've been craving animal products like eggs, fish and chicken. Previously even the thought of eating such foods evoked feelings of nausea. I still can't imagine eating them but I'm starting to wonder if "my body is telling me something." I'm really hoping this is not the case. I'd be very interested in hearing if others have had a similar experience.