I Have Been Sick With A Flu Since Last Wednesday

I have been sick with a flu since last Wednesday which has developed into a cough (severe at times). I started my period 2 days later (on the Friday) and have been experiencing heavy bleeding, more than normal, especially when one of my coughing fits begin. The first night I had to get out of bed twice to change pads(something I never have to do) This is now day 4 of my period and the bleeding is still quite heavy when I cough. Generally by this point it is tapering and I am able to get away with a light liner. Now I'm not sure if my lingering lethargy is a result of the flu or anemia and wonder if there is anything I can do to alleviate the problem.