My spots had gone when I was on the pill - things changed over the last four years and my skin was nice, although I had to use loads of moisturiser.
Since then, it has been one hormonal upheaval after another. I have two on my forehead and my back went greasy and now is all zitty again.
It helps if you keep hormonal stuff very level, always taking hrt at exactly the same etc (but that is no help if your own hormones are all over the place.