Ah sorry Banjo, I think maybe I wasn't clear about the utro/period connection! To clarify: my periods (pre HRT) were always incredibly heavy and painful, lasting about 10 days. Because progesterone keeps the uterine lining nice and thin, and utrogestan is progesterone, it tends to make people's periods lighter and shorter, as has been the case (thankfully) for me.
What I meant was, I wonder if using utro rectally will help the drug to be absorbed as well as it has been vaginally. If it doesn't absorb as well, then I would expect my period to be heavier again because the drug hasn't been keeping my lining as thin as it should.
So if anything, one would expect your periods to get even shorter and lighter on utro, as long as the drug is being well absorbed.
Sorry to add to the general confusion - I hope that's a bit clearer!