Hi Cagsey
It sounds like maybe your own cycle is overriding the hrt one. I had this also and was in effect having 2 periods per month, one 2 weeks into the month and then another when stopping utrogestan. So what I did was sync them up. When I started my natural period, I called that day one, then started the utrogestan 12 days after that and it's worked so far, I'm back to just having one bleed a month. You could maybe try that? Obviously it might not be that but thought I'd share my experience xx