Are headaches a common pregnancy symptom?

I grew up having constant headaches, which I later found out was most likely due to my vision not being a good as it could be. But I haven't had them quite as often in the last few years. However, all day I've had the worst possible headache, and well as yesterday, and nothing seems to make them go away for more than a couple of hours. It feels as if one of the vessels in my brain is about to explode. Is this normal or common for anyone else? I'm nearly 8 weeks along, btw. I've been stressed lately, but have never had a headache this bad.