Try taking MAGNESIUM!!
Of course check with your dr., but people who suffer from migraines often have lower levels of magnesium- This goes for pregnant or not pregnant.
Before my pregnancy, I took a daily medication to maintain my migraines. When I had to go off it, I started seeing a neurologist and he suggested taking magnesium supplements. He recommended starting with about 50-100mg a day, then if that doesn't help after a while, start upping the dosage. Your body can handle 400mg a day. This is what I have to take. It helps a lot!! I still get migraines and I take fiorcet (pregnancy safe) for the attacks, but they are not as frequent nor as strong- just like when I took my daily medication.
Also, B6 is very helpful in combating migraines. I promise, do yourself a favor and ask your dr. about it and Google it. It's true and it's more natural than prescriptions.