Headaches after miscarriage?

I miscarried about 4.5 weeks ago @ 9 weeks and I had a D&C 3.5 weeks ago. The last 2 weeks I've had terrible terrible headaches all day - every day!! My obgyn doesn't seem to think it's related and says I'll have to see my pcp....anyone else experience this? I've read that they says it's because of the drop in hormones.....any advice? Thanks :)