near constant ache behind my left eye

I'm a 17 year old girl and have suffered from migraines for years but only recently, i seem to have a near constant ache behind my left eye. Before Christmas 2009, I went to the doctor to change my medication and he did a quick general exam just because I hadn't had my migraines reviewed in a while and he checked my blood pressure and the like. He said that I seemed to be managing them fine so whatever it is has occured since then.
This ache is on the left side, where my migraines tend to be. Along with this ache I sometimes get throbbing pains at the base of my skull, on either side of my neck and my eyes find it very hard to adjust to light. I'm also very lethargic these days but always just get up and get on with things. Am I just being paranoid and a hypochondriac or should I go back and get checked again? Other that this, I am fit and healthy.

Thanks