I have low blood count, & I've started taking iron supplements. However, I am getting irregular periods now (twice per month). Is this normal?

Anemia. It is more likely that your irregular or heavy bleeding would lead to your iron def anemia rather than other way around. Iron can cause constipation or some abdominal discomfort. You may need to talk to your doctor about birth control pills or other types of hormones to help control your cycle.