Blurred vision

I'm 9w3d pregnant and I've been experiencing severe blurred vision to the point I can't see anything. I went to the ER and the told me it's probably from migraines because everything else checks out. Like no high blood pressure. But something tells me this isn't just migraines. I don't get a headache until it's been 10-15 mins of the blurred vision. Does any one else have the issue? All doctors gave me was magnesium pills. Anyone have suggestions?