I used to be on Topomax as a preventative and Zomig for treatment. Since TTC, I weaned off of Topomax, and my doctor recommended I try Riboflavin or Magnesium supplements to help as a preventative. I did my research and tried Riboflavin.
Before Topomax I had 8-12 migraines per month, after I had about 1 per month. Since weaning off of Topomax and starting Riboflavin, I'm maintaining my 1 migraine per month.
The only thing that sucks since getting PG is not being able to treat the migraine, I just let it run its course.
I also started seeing a chiropractor and found that my neck issues cause some migraines. I switched to a neck pillow and stopped sleeping on my stomach. This helped as well, sometimes you just have to try random things and figure out what works FOR YOU.
Good luck!