Thanks for your replies DG and Hurdity,
Yesterday, after about 3 days of the headache, as the day wore on I could feel it lifting - it was almost tangible as a feeling of 'being myself' (whatever that is haha!) came over me. I'd spent the afternoon in bed on Tuesday which helped and I also put my patch down to just over a quarter. I really do feel that the lower dose suits me better so I'm going to stick with it rather than increase. On this basis Hurdity I don't think I need to visit the GP although I note your advise and if it happens again I will do. I am interested in the regime you use as there may be a time that constant oestrogen and progesterone, albeit in small doses, no longer suits.
Vicky, I would stick with the lower dose and only increase slowly if needs be. As DG and H say, it is a very low dose; in fact I think that quarter of a patch might be regarded a ultra low dose. I too started on a third and went up to just over a half. I got some mild headaches and nausea but they passed. I only have limited knowledge on utrogestan, but from what I'v read on this site, it's not so much that it's safer, rather that it has milder side effects (but we are all different and there may be some ladies who don't get on with it!)