I'm surprised it's only 1 in 10 women that have problems with Utrogestan because without a doubt, it's the most frequently discussed problem on here.
I suffered Utrogestan for several years and on reflection, I think the side effects were worse than the Mirena coil in my case. I used it vaginally but it hardly made any difference to the side effects. I took it cyclically at a very, very low dose but it was always the same pattern, feeling OK for the first 3 days then I gradually felt myself slipping away which was very scary indeed. Next came the dreaded bleed (which made me feel ill) and very often I would have a silent migraine at this point. It took me about two weeks to get over the Utrogestan phase post bleed and it completely destabilised my hormones. This is very strange because I have no history of PMS or progesterone intolerance.
I finally hit the buffers with Utrogestan nearly two years ago and realised I could never take it again. Long story short. I now use 50mg bespoke progesterone lozenges and they are absolutely brilliant with no side effects and no bleeding! Take a look at my thread in the Alternative therapies section on here.
No everyone has problems with Utrogestan, some women love it but my view is the 100mg dose is too high.
Perhaps you could try a Mirena coil or better still, the Jaydess coil.