Lolabella, hugs hon. I REALLY feel for you. I also had to cave this morning and take some paracetomol, which seemed like they weren't going to work, but then I pegged some washing on the line and perhaps the fresh, cool air helped clear my head a little, then I was starving, so ate some cheese of all things (normally a headache no go!) with some soup, not at the same time mind, and it eased off on it's own.
I have read that headaches in pregnancy are caused by the increased blood volume and increase in hormones. Others say that pregnancy can cause tension in the spinal column which can lead to tension headaches (the kind I get). They can also be caused by anxiety (that's all us lot then!), hunger, dehydration, lack of caffine and certain foods.
I normally start off by making sure I am not thirsty and have a couple of drinks and then try a warm, relaxing bath. Sleep at the minute makes mine worse, I think I am having issues with my pillow.
I hope that you feel better soon, there is nothing worse that a constant headache.
Thanks for posting the scan list Creena, I can't remember where to find the list now, lol! It is helpful to know who is having scans!