Hi Silverfairy
I am on a similar regime to you although I take Utrogestan 200 mg.
If you go to the home page of the forum and search "Utrogestan" there are lots of threads with discussions about the different amounts.
In your case it depends what you have been prescribed and whether you are supposed to have a cycle or not, and whether you are peri or post-meno.
You will see the standard licensed doses here:
http://www.menopausematters.co.uk/to_progestogens.php100 mg utrogestan is usually given orally for post-menopausal women for 25 out of 28 days - or continuously and is designed not to give a bleed.
Quite a few post-meno women such as myself (and others on here) prefer to have a cycle (taking Utrogestan for 11-12 days out of 28 or a longer cycle) for the reasons you describe - that too much progesterone causes unwanted side effects eg bloating, fatigue, brain fog, headaches etc.
You haven't said the dose of oestrogen? Maybe 50 mcg? It sounds from what you are saying that you are taking it continuously so maybe an idea to restart a cycle - recommended for progesterone intolerant women. The downside is you would have a bleed, and you might experience the effects of "progesterone withdrawal".
For many of us, all HRT comes with some drawbacks - just as in our fertile years with our menstrual cycle. It is a question of which regime you feel works best for you and which side effects you can cope with!
I should add that it seems from reading on here that women under private gynaes (and some enlightened GPs) sometimes take less than the licensed amount of utrogestan, but they are monitored carefully to ensure no thickening of the womb lining. Used vaginally means you can take less than the oral dose and it is still effective in keeping the womb lining thin, but this is off licence.
Hope this helps
Hurdity x