Hi louloo
Sorry to hear about your symptoms.
Your doctor sounds great - it is so important for you to take HRT at your young age to protect heart and bones and for your general health.
In terms of migraines - transdermal HRT is recommended ( ie patch or gel) as it doesn't have to go through the sytem. This is what it says on this site (menu up top):
Migraine
Migraine is often triggered by hormonal fluctuations and therefore may occur around the time of a period. Such migraine may improve at the time of the menopause. Some women find that migraine may be triggered by the daily hormone fluctuations which can occur with oral (tablet) HRT so the transdermal (patch or gel) route is usually preferred with a history of migraine. http://www.menopausematters.co.uk/atoz.php#GlossMI started getting migraines (without aura) when I became peri-menopausal - the headaches were persistent and nagging, but not usually throbbing, and lasted for three days - but the exhaustion and persistent nausea, and heavy head contributed to how debilitating they were. Fortunately for me they weren't usually the confining to bed type - although sometimes for a short while. They continued through menopause and on certain types of HRT. I still get them now and again but not so badly.
I have always used transdermal HRT so I would start there. Fortunately, because you don't have a uterus you don't need to take a progestogen and it is the fluctuations in this and some of the synthetic types which can cause headaches.
Whether to use patch or gel is a personal preference - gel has to be applied daily and patches usually twcie a week. I use Estradot which are very small and stick well but as you are young you might not like the outlines they leave on your buttock (which is where I stick them!).
Hope this helps and I'm sure someone will be along later with their experiences
Hurdity x