I've recently been prescribed hrt and am already totally confused as to when I should start taking it. I haven't had a period for 3 months so no idea if or when it will start. The utrogestan says I should take on days 1-25 of cycle, but how do I calculate where I am in the cycle? Or do I just wait until I get a next period and take that as day 1? Or do I try and work backwards through my previous periods ( I have dates logged on app), to see what day I should be on, if that makes sense? So confusing !