Rosieray - As already said, estradiol levels will vary according to your cycle and although you say it is the same point in the cycle, if you are perimenopausal then it is most unlikely to be at the same point because peri-menopause is defined by irregular cycles! I mean if a cycle is regularly every 22 days (without HRT) then this is not peri-menopause but the last stage before. Also levels will vary according to time since patch change, and possibly also with time of day due to circadian rhythms, and also skin temperature which will affect absorption.
It may well be also that the dose of utrogestan is insufficient hence the frequent bleeding ( as well as your own cycle coming into play). I agree that the return of flushes usually indicates insufficient oestrogen, having ruled out other causes. As joziel says also you may not be absorbing well. Have you tried gel or spray?
250 isn't a high reading and is a tad too low to be optimal in terms of bone health, where you want 400-600 for most women (according to my Newson doctor).
I'm curious as to where this very high figure comes from - I have not read anywhere that these levels per se were optimal for bone health, though I'm not up to date. The dosages licensed for osteoporosis protection are only medium doses and I doubt would consistently give levels this high. In my case, (only one example!) my levels on HRT have been around the 200 mark I think most of the time though since I increased my patch slightly they haven't been measured but I doubt much more though - but as I understand my bone health is good (haven't had a proper bone scane though) - even at my advanced age (70), I have not lost any height.
Hurdity x