What Causes Heavy Bleeding Periods And Headache?

hi i am a woman have 46 years i got a havy bleeding in my last period the doctor gave me a primolut=nor to take it for 15 days the blood stop it after 2 days but my problem is i feel like i have a headace in the back and i feel that ia m nervous and i can feel it that i am not stable as before so i want to know if it this side effect i s from this medcin or from efficieny in iron in my body , what is the sign of efficiency of the iron in general