If your doctor doesn't recommend you use it... is there a reason you want to? It's not necessary unless you're having the symptoms that it's prescribed for (primarily vaginal dryness), and if you do use it, you should make sure your hormone prescriber knows you're supplementing with additional hormones.
I also had normal vaginal tissue when my GP examined me at 4 months post-op, and his recommendation was simply to use a slightly better moisturizing lube (Vagisil, which has no estrogen added) when I dilate, as things seemed a little dry in there. That became less of an issue as time went on, and now I'm comfortably moist all the time.