You haven't said how long you have been on Evorel conti? Some spotting and bleeding is normal for up to around 6 months when first starting continuous combined HRT so if you are within that time frame then no need to worry especially. If you have only just started taking it then the headaches could be due to your body acclimatising to the added hormones or it could be due to taking the progestogen all the time - the one in Evorel conti - norethisterone - is notorious for casuing various pms symptoms. Often the side effects will settle but the recommended time to wait is 3 months because your body is still adjusting.
Unless you are especially sensitive to added oestrogen it is doubtful whether 50 mcg oestrogen is too high if you are post-menopausal because the level is nowhere near that which you will have achieved naturally when fertile and menstruating.
Depending on how long you've been taking it I would carry on until 3 months. Otherwise if longer than 6 months then see your doc about the ongoing bleeding. If nothing is amiss you could try the sequi version ( Evorel sequi = 2 weeks of Evorel 50 oestrogen only, followed by 2 weeks of the combi patch Evorel conti) which would give you a bleed.
Alternatively as you say you can use a patch with separate progesterone (as I have been doing for many years quite happily!). I don't think your body will get confused - the two hormones are separate anyway - it will just absorb them and use them.
Good luck with your GP, try not to worry and let us know what you decide.
Hurdity x