Hi! I have very regular menstrual cycles. I am healthy & work out regularly, I'm 37. Due to holidays & a stressful theatrical musical my daughters were in, I have not workout a lot & ate poorly. Now I have started bleeding 10 days before my period is due - very rare for me. This is my 3rd day & it's stil steady. I feel a little light headed too but just sometimes. Any explanation of what could be causing this?